Because of your medical background I think you are taking those who say “sugar is a drug” too literally.
It’s not so much how it chemically reacts in the body compared to a drug… it’s our emotional dependence on it, cravings when withdrawn, and pleasure when partaken that are similar (not exact) responses.
I always mentally pat myself on the back that I don’t care about sugary foods and can take them or leave them. My husband quit buying me chocolate for Valentines Day years ago when I would have a couple and the box was still sitting on the counter in June.
However! I had a revelation this past week when I was close to breaking my 72-hr fast. I love sweetener in my coffee (and cream) and really miss it when fasting. I mean really miss it. I was literally watching the clock with my packet of Truvia in my hand waiting to add it to my coffee. I sucked it down like it was a magical elixir and it definitely fired the pleasure centers of my brain.
Anyway… back to your topic. You are young and healthy with your whole life in front of you so your options are not as limited as mine (age 60, cancer survivor, years of insulin resistance and overweight). I am healthy, at a healthy weight and am looking at the tail end of my life with all my neighbors 10-20 years older than me and observing their health issues and decline. There is no “after keto” for me. I don’t want to be them. I know I can’t stop the clock but I can be healthier than them and for me that means keto for life.
For you… you just need to find a balance between keto and eating sugar all day. It will eventually catch up to you - no doubt. Not if, but when. May not be for decades.