Have you tried making some good bone broths? It really helped improve my gut problems and digestion. I too used Accutane during high school and shortly after I experienced really bad allergies and digestion/reflux issues. Eliminating grains/gluten and dairy helped massively. But in order for me to really rebuild my gut I followed the GAPS diet which included a lot of mineral rich bone broth, fermented foods, as well as some good probiotics. Protein alone without a good fat source tends to make me lethergic as well. Just as long as I have some good healthy fats in my meals I don't get sluggish.
I used to do the chronic cardio thing too and I was logging 5-10 miles per day. I have such better results now just running sprints once per week and walking more often. Are you still doing that much cardio as well?
"If man made it, don't eat it" - Jack Lallane
People say I am on a "crazy" diet. What is so crazy about eating veggies, fruits, seafood and organ meats? Just because I don't eat whole wheat and processed food doesn't make my diet "crazy". Maybe everyone else with a SAD are the "crazy" ones for putting that junk in their system.