PLEASE HELP: I think I'm crazy..or I need to be in an asylum.?

I love being alone, and i feel crazy when I'm around other people. I don't want to bore anyone, because if I explain every situation where I felt crazy, no one would read this because of the length. I guess what happened today could explain, today we had a group work, so I didn't know the answer so I just copied from one of my groupmates, but then I felt so guilty about it...I didn't finish copying the work, and just passed it to my professor and I told him I couldn't finish. Then I went to the bathroom and preceded to cry and cut myself. I said sorry to my groupmate, who is also a boy I have a thing with, he said it's ok, and everyone was copying from each other anyway. But I felt bad because I didn't contribute. I feel useless, no good. I just can't be around people or do group work. I CAN be around people, like, at a party for example, yeah its ok because I know I'll never see the people I met ever again for another 6 months or something. But with my classmates? people I see everyday? I want to die. I feel so crazy, like I should be in an asylum. I don't feel normal..i tried talking to the guidance councilor, and she said my self esteem is too low, which makes sense cause I don't talk to people because I don't want to bother them. I don't want to do a groupwork because I'll just be no use. I can't help but feel that way, because its true! Today, everyone had a book in their hand and everything, but I didnt, I just couldn't for some reason. Please don't force me to be more outgoing. I just can't do it, i just want to know if I should be in an asylum.. I also think I need glasses, but I don't want to bother my mom about it cause shes already spending money on my tuition fee. I don't want to spend any more of her money on glasses. I'd try to find a doctor but those cost money, and I'm young, 17 years old. And I don't have that kind of money. And if I DO go to a doctor, I'd be a disgrace, everyone in my family is picture perfect, smart, successful, scholars, deans listers..