This just in:
People who have had a more 'normal' life generally pick up a few interests and hobbies along the way. We got to adulthood without exploring anything that we might enjoy or have talent in. Over the next year, try fifty things you want to do. That's not the big stuff like working out who you are, figuring out the meaning of life etc. I just mean the little things - hobbies. Try cooking, dancing, join sports teams, try bodybuilding, yoga, mechanics, kitemaking, trainspotting, literature, birdwatching, car racing, painting, studying, gardening, movie clubs, chess, volunteering, warcraft... you get the picture. Do it all. Start filling the big hole in your life with other stuff. Eventually you've gotta hit something that really takes your interest, and that you are really good at. That will be fantastic for how you feel about yourself.
What is working for me, now that I'm free of the concepts of my childhood, is study (doing a degree) and volunteering. The first is great because I'm learning that I'm pretty smart and that there is SO much out there. The second is great because I get to compare my life to other people whose lives are really considerably crapper than mine. That's really what has gotten me out of my bubble. I'm grateful I'm me now. When I was depressed it would have been no help at all for somebody to say that to me, I had to see it for myself.