No one believes in me, I don't even believe in myself, How can I find confidence

I am 20 years old, in college, a guy whose overweight, gay, and so many issues. I am in debt from college, no scholarships, 2.5 G.P.A and may not be even able to go back due to an enlarged bursar debt. I haven't had confidence for a while now, since freshman year of high school I have had trouble. I always just tried to pass I didn't care about succeeding. But why is that? Why is it that I don't want better for myself. I have been depressed when I was in college. Made a 3.0 freshman year in college, and then it just deteriorated since then. Even before that, when I was preparing to go to college. I signed up for classes late, I just let things get way out of hand. I remember a conversation my cousin had while I was staying with them preparing to head off to my university. I hadn't signed up for classes yet, and other family members new about this. She told me that I was synonymous to "leaving a baby in a forest" Sure growing up my grandmother gave us whatever we wanted and protected us from everything. But she was a good grandmother cleaning up my mother's messes. My mother couldn't even take care of us. But she is so quick to have a conversation about how I need to step up to the plate and help out. To be honest if I wasn't in college, if I was just another 20 year old sitting at home, she wouldn't have a problem. they don't even take time to acknowledge the fact that I am in college. They just don't care. How can I find confidence in myself. I would love to lose weight, go off to graduate school become a cognitive psychologist. But It doesn't seem like its going to happen. where can I find confidence, how does one acquire it. if someone is looking to help it would be very good. Thanks