I know exactly what you mean.. the feeling of not wanting to go out, be near people, even if you know them or have met them alot.
I am engaged and have been with my partner now for almost 3 years but i still cringe when he asks me to go to his parents house for dinner, or go to his friends christening etc.
He doesn't fully understand why i feel this way dispite my trying to tell him how it feels for me,
it is hard, but i think pushing yourself to do little things, baby steps if you will, to get yourself back into the social side of things will help.
As hard as it feels, there is only you who can make you do things.
Only you who can tell yourself... that being out, even if its just for half an hour will make you feel a little better.
I avoid going out at the best of times, but when i get there and relax (eventually) i feel glad that i have done it, and it makes me feel a little better about myself.
Just take deep breathes and try to relax,
and remember.... YOU are as good as everyone else!
I hope this finds you well, and helps you like it has me xxx