You sound motivated and that is a good thing.

Vitamins are important, especially from their natural source (food).  If you take supplements, which I would recommend, take them with a meal in you.  If I take them alone, I feel very sick to my stomach.  I also have learned that with the B vitamins it is important to take a multi-B, not just one.  Otherwise, it wacks all the other B's.  Too much C can give you a headache, but I think C is important for your immune system.

Take it one day at a time, one moment at a time if necessary. For sleep the best thing I have found is Valerin Root.  WonderLabs is what I take.  It is natural and does wonders for your body.  It will relax you slightly so that would be good for your stress level as well.  You can buy it on Amazon.com.

Keep posting.