If you've been emotionally or physically abused, or if you grew up in a house where nobody paid much attention to you or your feelings, you will probably attract friends and lovers who treat you the same way.
Just so you know, I'm not a shrink. I'm licensed to drive, and that's about it.
But I've noticed that people who've suffered rotten relationships in childhood tend to end up in rotten relationships as adults. If this sounds like you, you need to create in your own mind what a good relationship looks and feels like. You have to, as Wayne Dyer says, "picture the end result," and put yourself in that picture. You have to feel yourself in that picture, and you have to do it over and over again until you realize it. "Fake it 'til you make it," Steven Tyler from Aerosmith once said.
It helps to get away from people who are down on the opposite sex, who believe true love is a myth for suckers, and so on. Hang around with people who enjoy good love relationships. Absorb their good luck. It's contagious.
Recognize the fact that your past relationships weren't ideal, but don't feel sorry for yourself. Move on. Believe that the love you want and desire wants and desires you, too.
Keep at it until one morning you find yourself waking up next to a man who cherishes you the way you were meant to be cherished.