>>8 is right, but you don't have to stop liking anime/manga, or whatever your main otaku interest is. New hobbies are a great idea, preferably something that improves you as a person (sports, music, whatever).
Some things to do to make you feel better are
- Groom yourself and give yourself a nice little makeover. It is the inside that counts, but if you look nice on the outside, you are sure to take pride in it.
- Talk to people. Talk to your friends, your old classmates, parents, family, anything. Interaction is always great.
- Set up things to do, and do them with enthusiasm. I personally hate thinking about have to do thing, but when I do them, I always feel great.
Just some tips, use or don't.