I have the same issue. I don't have any friends at school. I wasn't abused at home, but I was abused by my ex-boyfriend of 5 years and I was so severely bullied up until I graduated high school. I always hated the advice people gave of, "just relax and try to start a convo up with someone and see what your interests are." Like that's not how it really works when you have anxiety. I get upset sometimes too, but the way I get through it is telling myself I'm there to learn and I need to keep focus on my school work and not worry about making friends. Put yourself in a situation that makes you feel comfortable whether it be just focusing on your school work like I do, or if you are able to just walk up to people without anxiety go for it or join a club. Don't feel bad though about not having friends. Or sometimes I find that the best way to get involved is to find something that pertains to your major because that's where you will feel the most open and real with yourself and that will show with others around you.