The feelings you describe often go with social anxiety disorder. People with this disorder are anxious about being with people because they have an irrational fear that they are being constantly judged by others. In your case, you avoid people you don’t know and stave off your worries about people you do know by being overly responsive and self-sacrificing. It’s as if you don’t trust that your friends like you for who you are, not just for everything you can do for them. It’s very painful.
The good news is that cognitive behavior therapy has been found to be especially effective in helping people get more comfortable with the social world. Generally, such therapy is short term, lasting only 3 – 4 months of weekly sessions. Analytic type therapies, on the other hand, are often not helpful because they tend to set off even more obsessive thinking.
I encourage you to find a cognitive-behavioral therapist to help you get past these feelings so you can be relaxed with people. If you can’t do that, there are self-help books on the subject. I was also able to locate several online support groups for people who experience social phobia by doing a simple search on the Internet.
You seem like a very nice person. I hope you will follow through and get some kind of treatment so that you can have more fun and be less stressed when you are around others.
I wish you well.