How to get back on my feet and feel strong again?

I was on a trip which I had won and I felt so healthy and normal, but when I am back home in a 1 bedroom apartment I share with my parents I feel sick -- literally flu-ish-- and weak all the time and can't go outside the house (and feel anxious when I do). I was thinking of moving out and finding work and declaring independent status-- but it sounds weird-- I feel too weak to do so. I used to think I was too weak all the time to go anywhere or do anything, but now I know this place is making me sick and anxious. Any suggestions for getting back on my feet?