My life is surprisingly similar to yours, so I can sympathize. Unfortunately, because of that, you'll have to take my advice with a grain of salt. It's like the blind leading the blind.

I think the main reason most interpersonal connections fail is self-centeredness. You have to think and care about other people before they'll care about you. Let your heart go out to other people and then you can forge a connection.

When you talk to somebody at work/class, try to figure out what they would want you to say or ask them. It takes a lot of practice to read the signs and figure out how to best connect with people. I'm still working at it.