I have followed the keto diet for over six years and I did a carnivore trial for seven months at one point. I have had to supplement extra salt the entire time I have been keto/carnivore. I’ve tried cutting back many times but have suffered the consequences every time. When my salt intake is too low I get low blood pressure (90/50) , muscle cramps, general achiness, and headaches. You may be one of those people who has to keep your salt intake high.
Something else for you to look into is oxalate dumping. I don’t have time to go into the details here, but carnivore is the ultimate low oxalate diet and when one stops eating all oxalate containing food their body starts dumping the oxalate it stored up over the years. Vision trouble can actually be a symptom of it. Dumping usually begins with two to three weeks of removing oxalate from the diet.
We have some info here on the forum if you search on oxalates and there is a lot of info on the web, especially if you look up someone named Sally Norton. She is an oxalate expert.