Social anxiety is a strange animal. I've been dealing it with for over 20 years now, and I'm afraid I don't have any ready answers for you. I think the root of it, at least for me, is self-esteem. Feeling like you deserve friends, you deserve to be treated well, you deserve to have your opinion heard and have someone be there for you. The right people will understand how to deal with that, to be close when you want and give you your space when you don't. And honestly, it's hard to make friends once you're out of school because you have so many other responsibilities and demands on your time. But if there's a club you'd like to join or an activity you've always wanted to try, make the leap and you might make a friend. At least you'll prove to yourself that you can step outside your comfort zone and not get your foot caught in a bear trap. Good luck, and good hunting!