That happened to me awhile back.

I wish I had some insight, but in my case "luck" had a lot to do with both the problem and the solution.

People have told me that sometimes it helps to increase the number of one's acquaintances to give "luck" a helping hand.

Other people have told me that changing venues can sometimes help. So if meeting people in schools and libraries isn't helping, one could try bars and nightclubs. If that doesn't help one can try volunteering in various organizations and so on. I guess the idea behind this is to bring in more acquaintances and more different kinds of acquaintances.

To be honest, my problem was solved just through luck and I have never tried these techniques. I hope you get lots of responses to your post and that some are really helpful. It can be very stressful and painful to not fit in anywhere.