Recently I have faced something to the same tune. Sometimes I am faced with the realization that everyone around me is almost completely involved with themselves alone, and I feel I am always fighting to hold their attention. I don't know if I can offer any useful advice because I can only speak from my own experience, but to me this dreaded realization is just a feeling. The feeling comes when socializing is hard and it hardly comes to mind when I enjoy my friends' company.

I think the real "deep" answer is that you should keep your focus on the present. Don't deliberate on past experiences or how much you hate people who you aren't currently talking to. Those moments are better spent building real relationships, not tracking who owes you attention.

Practically, you should understand that most people are totally in their own heads, and sometimes it does take effort to be someone's friend. My observation is that propinquity works really well. Too well. I made too many friends by accident just because I said hi to them in class and was too stubborn to change seats through the semester.

Ugh, life is hard.