I sometimes think giving complex clinical terms to phenomenon can make matters worse. The situation you're describing sounds very similar to me, but I attribute it to simple depression. When depressed I sometimes get almost agoraphobic & have lost friends because of that. Similarly I feel a decreased joy in general when I experience that with people. In other words, I know (I think) what you're feeling. Maybe if you think of it as simple baseline depression you won't feel as isolated/"odd" as you do now? Just a thought.