I can relate to what you are saying. But it's a part of this negative cycle "we" get ourselves into. When you say to yourself that you are not a worthy friend, you will believe it. And eventually your friends hate your negative behaviour, and will not keep in touch anymore. Confirming your belief that you are not worthy.

I am trying to break this negative cycle, just with some positive thoughts. It's not getting me anywhere, but it makes me feel a bit better.

Replying to your message even makes me feel a bit better. Because, even though I think I'm a lost cause, I can still help/support others.