I suffer Clinical Depression, and the past 5 years I’ve lived a very sedentary life, and lived on sugar-filled processed foods & carbs. A friend got me on the Keto diet, and the first strawberry I ate was a revelation. I went full on, and the first week I lost 12 lbs (mostly through pee it seemed) and I was happy & energetic. Now, midway through week 2 my body is so severely fatigued its hard to walk! People still tell me I sound better on the phone but I feel like I have some wasting disease. I mean, I was terribly out of shape already but I could walk, vacuum, clean litterboxes…the first time I did the 6 litterboxes on keto I started panting and almost passed out. I don’t eat red meat, but I am eating fish, chicken, turkey, eggs, the approved fruits & vegetables, hummus, & guacamole. I try to sprinkle the meat with sea salt. What is happening, I’m freaking out!!!
I've looked but haven't seen a post about extreme lethargy
Maybe more salt?
Maybe more water?
Are you eating enough? You don’t really need the fruits, I have them as a rare treat.
I don’t know how many people here had the extreme lethargy you did, but lots of people did have lethargy until 4-6 weeks after they started.
You are always welcome to post what you are eating so we can analyze it. 
Good luck and hope your energy returns soon.
Welcome to the forums!
Making sure you get enough salt is a good idea, and also, don’t cut calories. If you are eating low carb, you can afford to eat to satiety, and let your appetite determine how much to eat. The low insulin resulting from the low carbohydrate intake will allow you satisfy your hunger, while still allowing your metabolism to re-regulate itselfe and your fat tissue to release fatty acids to be used as fuel.
Hi Melissa, and welcome. 
What @PaulL and @KetoCancerMom have said. But also, I’ll add that your body is now getting used to a very different kind of fuel. It takes a while to adjust, but it will happen! So drink water, swallow some extra salt and maybe magnesium, and eat plenty of fat. Than start reading through the other “Newbies” posts. It’s a good place to start learning the ins and outs of this keto thing. 
Welcome to the forum, Melissa =).
You are just going through some carb and sugar withdrawal, it will be over once your body gets adjusted =).
Just focus on keeping your carbs 20 grams or less, NO sugar, eating adequate amounts of protein, healthy fats, and getting enough calories, and drinking a lot of water and keeping your electrolytes up. Getting enough good salt is really important on Keto =).
cronometer.com is a free app you can get on your phone/tablet/laptop/desktop and can make an account and type in your age/height/weight and it will tell you how many carbs/proteins/fats and calories you should be having, and what you are actually getting from the foods you are eating. It really helps and helps to keep you on track so you can figure it all out =). Try that and type in everything you are eating, and then if you have any questions, just ask away, we are here to help =).
This is a great forum recipe to make Ketoaide, an electrolyte drink you can make yourself:
I think it sounds like your body is in a recovery phase. Its transfer out old, process in new.
Let your body rest, don’t force anything, and definitely stay on the ketogenic diet.
The lethargy is because your body used to use sugar as fuel. Now you are not eating sugar and your body cannot yet use fat efficiently as fuel. Make the ketoaide. That will help. So will eating more fat at meals, especially if you find you are still hungry after a meal. Just hang in there. Once fat adapted, you’ll have energy to spare
I had extreme lethargy when I began again this time. It felt like I was trying to run through waist deep water all the time. It lasted about 3 weeks full on, then started easing up. I don’t know when exactly I began having lots of energy, I just noticed one day that, wow, I felt great! I also learned that I needed to limit my eating to 1-2 times a day and no snacking. When I was starting out I was told that there aren’t really any such things as Keto fruits, and to keep my carbs below 20 grams a day. Eat only meats, fats, and a few low carb veggies until I got adjusted. I believe that completely cutting out fruits and other high insulin triggering foods helped me get over the lethargy.
I did read through all the newbie posts and read some “tired” posts, but this is like, my legs shake when I walk!!! I feel like I’m eating all the time, I’m putting salt on everything, but I’m craving sugar desperately!! And I’ve upped my water intake. Thank you!
Sorry, I was on my phone and it came out with “pay” instead of “post”. 
It would also help to know your age and height, if you don’t mind sharing. But mostly, a representative day’s food should do the trick.
I’m 54. I used to eat healthy and worked out all the time. But after several life traumas, I ended up alone with cats (my family). When healthy, at 5’8" my best weight was 145. After I was diagnosed with clinical depression & ptsd, put on meds & therapy, the world was a scary place so I became a shut-in, snacking all day on processed chocolate granola bars, ice cream, peanut butter & the only fruit I ate was bananas! (I hear the groans). I gained 55 lbs, which just got me more depressed & isolated. The first week on keto I lost 12 lbs and felt fantastic! So it puzzles me I went down so fast this week. I do eat quite a few salted almonds, but I read on here that is not good. I also have not eaten red meat or pork/bacon for 30 years, and cannot start now. So I know bacon is a staple for ketoers, not sure what to do about that. I’ve switched from almonds to olives, which taste awesome & extremely salty. Sorry for the life story but I feel like I have extra challenges as a keto eater. I haven’t weighed since, but I wonder can rapid weight loss cause fatigue? Thank all of you, thank God I found this site!!!
It is true that a lot of people on the forum love bacon, but some of us rarely eat it, it is not a necessity by any means, so don’t worry about that =).
I am 54 as well, will be 55 in November.
This is really awesome! Way less carbs so that was an excellent choice!
If you use Electrolytes, get enough salt, then you will recover from the fatigue you are feeling, that is caused from lack of electrolytes, and carb and sugar withdrawal.
You can make this, or just make sure you are drinking a lot of water, and a good salt, like Pink Himalyan salt, take a few teaspoons a day (you can either eat it and then drink a lot of water with it) or add it to water and drink it, and put it on your foods as well =).
I love salmon and chicken and end up eating a lot of them as my proteins. Everyone is different, and Keto is very versatile, you can modify the foods according to your preferences =).
Just keep your carbs 20 grams or less, adequate proteins, healthy fats, no sugar, and lots of water and your electrolytes and you will be okay soon enough.
Thank you so much for the KetoAide electrolyte water! I will drink that all day. I just can’t, yet, eat a spoonful of salt…I mean I was an extreme sugar addict! And I never salted anything because I didn’t want to retain water…I know, I know! Hard to lose those old rules. When everyone told me “more salt, more water” my brain said (that’s going to bloat me!) But of course it won’t.
For sure, I am the same age as you, so we were taught to have low fat, lots of fruits and vegetables, but Keto is the opposite of this, and we have to retrain our minds and our bodies! We are all here to encourage you though, so please stick with it and we will all be cheering you on =).
Thanks so much Susan…people knowing what you are going through and knowing how to help and encourage you is priceless! I just downloaded the cronometer, hopefully I can pull myself out of this sooner! 
I found personally that the salt really helped =) with the fatigue, dizziness and leg cramps so I think you will find it helps you lots too =).
Thanks. I was only eating strawberries & blueberries, but I’m still not out of snacker mode, so I’m sure I was eating to many. No fruit until I can walk normally again!
Salt will help with fatigue, but there is a certain amount built into the switchover from burning glucose to burning fatty acids. The good news is that after 6-8 weeks, you should have all your energy back. I didn’t particularly notice, because of a number of major life events that piled on at the point I went keto, and perhaps that was a good thing. But people who do some form of exercise generally do notice, and if you work out in some way, give your body a break by easing up during the adaptation phase.
Be sure to get enough protein. You need somewhere in the range of 1.0-1.5 g of protein/kg of lean body mass/day. Then fill in the rest of your calories with fat. Olives and avocadoes are good sources, if you’re not comfortable with animal proteins and their associated fats.