Are these people really rude, or are they being too honest? Not in the way that they are saying honest things, but are they just being who they are? Are they just being honestly themselves?
I have felt vey much lately, very extremely, that I have never been in the right setting. I would say, "My whole life, I have felt friction between myself and my surroundings." But I think I am moving past that. I am exactly who I am supposed to be. I can be no other. Everyone you meet are being exactly how, and who they are, because they can be no different.
If you can accept who you are, and even accept that you really should be feeling like you don't fit in, you might find you actually feel better. If you can accept that those people are what they are, you may even find enough humor in it all to laugh a little bit.
I think I should qualify my ideas a litte, though. I am not condoning ignorance or rudeness, but people just are who they are. That feeling of not fitting in comes from the disconnect from how you think things should be, and how they really are. Where you find people, you're likely to find rudeness, ignorance, mistrust, destruction, and hatred, but you'll also find love, compassion, laughter, and creativity. The good and bad are equally necessary.