I am sorry you have problems keeping friendships. It isn't an easy thing to keep. I never thought about it why I can keep so many friends. Maybe it is because they don't see me very often since they live all over the world and we don't have much contact - LOL!
I was told recently that I am a lively person who likes to do lots of different things and that's why my GFs like me. Maybe try not to burden others with your problems (you probably don't, but just a thought). You seem to go to so many social events that you really should make friends easily.
I know I have not meat any guys I keep in touch with apart from my "hiker" whom I meat occasionally. But meating a new partner is a totally different thing from making new friends, and I seem to make some men nervous, why I don't know but obviously it is a negative thing.
I wish you good luck with making some friends. (((HUGS)))