I Have No Friends

I can't say no friends but very few. The people I considered best friends hardly ever talk to me anymore. I invite them or tell them I am available whenever they are but then I never hear back. it's been months since I have seen or had any kind of meaningful conversation with them. The girl I had feelings for cut me out of her life saying I didn't do anything wrong, she just didn't feel any connection with me anymore. I just don't have any close friends anymore, and I am told I haven't done anything wrong. I wish I had done something wrong so I could fix myself.