I have felt almost exactly the same way before. I've come to realize that it was my own fault. For me, recognizing what caused the problem made it a lot easier. Not better but easier. I am very shy so going out and meeting new people is very hard for me. I also suffer from social anxiety so that plays a huge factor. When I'm depressed I isolate myself. I don't contact anyone after awhile because I can tell I'm just upsetting them with my pity me party. Then I was angry because the only time I was contacted was when people needed things. I used to be the person people came to for support, but I turned that switch off, without realizing it, because I felt no one was there for me. When depressed you sometimes cannot help it. I moved away from everyone to start over. Now I'm alone because I chose a new path. One to discover myself and my needs. I really hate being a burden to people. Idk I just think discovering your personal part in the finding and keeping of friends, is the most important one.