We've all been in relationships that made us hurt. Everything started out well but at some point we stopped seeing and being true to ourselves and we began to hide all that was unpleasant, painted it in illusion colors, refused to see what was actually real and eventually fell into a pattern that we knew. A pattern that led to suffering each time.
I know it's not easy to change and break the pattern, believe me I know. But I also know it all starts with yourself, you are the only one to choose and be responsible for your decisions. Take a moment and ask yourself what about what I want? and what about how I feel? and try to follow the answers.
You might need all the courage and strength you can get but you would be able to put a stop to all the hurt in the end. You can change, you can discover new ways of relating - there are always new beginnings, there are always resources to move on. Keep in mind that you are never alone and on the path that you take you have friends and people who care. You can ask for help when you need it, but the truth is you are the only one who can take the first step to your happiness.
Oh, and it's never too late.