I think you are right. When you accept being treated poorly, it is a pretty good indicator of low self-esteem. If that is your problem, then only you can fix it.
You need to make some rules about what kind of treatment you will accept from people, and refuse contact with those who don't meet the standard. For example, I have decided that my friends, the people who care about me, will call occasionally and check up on me. Those who don't, aren't my friends. Lo and behold, that shortened the list of people I needed to send Xmas cards to.
I have a rule that I will never be anywhere where I am not wanted. Anyone who even hints that they don't want me around will never see me again. Life's too short to waste it trying to get people who don't like you to like you. Move on to people who do want to be around you.
I have lots of friends. And if I need more, I go out and find some.
