My wonderful boyfriend...

When I started my relationship with my boyfriend, 3 years ago yesterday, I knew that our relationship wouldn't be easy. Why? He's twice my age, married, and has kids. I wanted to give the relationship a shot in hopes of it working out. I know I'm an idiot for trying but I truly love this man. I've given his absolutely everything that I have to give. He was recently separated from his wife and I jumped to his rescue. I moved in the day she moved out, cared for the kids, kept the house clean, cooked, you name it I've done it. I've been busting my ass proving to him that I can be a much better partner than his wife ever was, especially since she abandoned him and the kids. She came back this weekend to "see the kids" but ever since she got here shes been on the phone ignoring the kids, she drags him off to talk to him and I feel like I'm nothing. I've been trying so hard and it's not enough. He's going to let her come crawling back just so she can do this to him again, she's already done it twice before. I don't know what to do, or how to feel, or who to trust... I feel lost and confused. I've ruined every other relationship that I've ever had to be with this man and here he is throwing it all in my face.