Madea says it better than I can:
Some people come in your life for a lifetime, some come for a season. You gotta know which is which. And you're always going to mess up when you mix them seasonal people with lifetime expectations. They got people who got married with people they were only suppose to be with for a season and they're wondering why they're having so much hell in their life. That was suppose to be a person that was suppose to come and teach you one thing and you didn't know it so you just fell in love and now you wonder why you ain't got no peace nowhere you go.
Ain't nobody said its gonna be easy. But it'll get easier when you learn how to love yourself. When you get to a point in your life where you look at people and you go Ok, wait a minute. You or me. You WILL make a decision. I've never told nobody Don't bother me anymore, don't talk to me no more. I've never done it. But what I do, is I tell them Look, this thing you're doing right here, that's gonna cause a problem. You need to fix that cuz if were going to be friends and were gonna be cool, you gotta fix that. And if you don't, then were gonna have an issue. If you see somebody fix it or even TRYING to fix it, then that's somebody that cares. Keep them people around. That's a leaf that's trying to grow up and be something else. You understand? But if you tell somebody that what you're doing is hurting me and I need you to stop it and they keep on doing it, they don't care. Move on. Let them go. No matter how much it hurts, let them go. And it'll get easier. I promise you. Everyday, it'll get easier and easier and easier. You just gotta make it through. You hearin me sonny?