It doesn't sound like anyone hates you - more like they don't appreciate you, possibly due to sensing low self esteem on your part.
In an ideal world, people would be nice to each other just because everyone deserves kindness; in reality, people might "kiss up" more to those they perceive as higher status, more confident, richer, cooler, more popular, fashionable, etc. and are dismissive of those that have low self esteem, even though the latter group may be quite kind and thoughtful. It's really silly and immature of them! I would advise to stop trying to get validation from random people, and focus your attention and love on the people closest to you, who really matter.
It's also possible that, since you were rejected in childhood, you are unconsciously drawn to people who don't appreciate you, in an effort to be validated by them. Why not train yourself to be drawn to the people who DO like you, and don't pay any attention at all to the ones who don't?
It sounds like you are perfectly nice to everyone, but your self esteem and past history are affecting this unfair treatment from some people. If you are depressed, it can also affect how people react to you, and then in turn you might also notice and feel the rejections more.
If it really bugs you, then working on your confidence, and trying to "fit in" more might help. Or just don't change a thing, and focus on the people closest to you, who really care, who really ARE worth your time, and try not to let it get you down about the others!