Why???

I don't understand. I'm with an amazing man and love and care for him very much. My ex is dating another girl and I get to the point where I think everything will be ok between us. I want him to be happy but at the sametime I don't. I want him to want me back and I know I dont want to be with him anymore but somehow he gets me wondering if I should. He misses me and all the times he left me and cheated and all the pain and head games. Some how he still works my head. I did good at ignoring him for a while. It has to be habit or something but I seem to want to talk to him more than the man I'm with because he knows all my messed up feelings and mood swings. I know I fear letting Chris (kinder love) get to know me and he sees alot of me. But the ex knows. I'm in this relationship and he has two kids of his own I have 3 and his oldest has a mother with my issues and I know she wants him back but he doesnt want her. But she is still the center of most our conversations and the other one he has a daughter with. His daughters mother is the one I fear, I think she is the one who can take the life I want away. Anyway His oldest has his mother in his head all the time. He used to hug me and get really excited to see me. A week ago at one of his games he told me he loves me (nothing new) but his mom was right there. About two weeks ago he hugged me and said "why is it when I hug you it feels like you're my real mom?" His words hit my heart and in no way have I tried to take that place. When he would call me mom his dad and I would tell him that he has a mom in a kind and gentle way. But slowly things have changed he started saying you're not my mom I dont have to listen to you when I ask him to do something (under his breath). He stopped getting excited to see me and doesnt hug me like he did before. He's grown short with my boys when they were close before. Everything flipped. Now the ex is messaging me saying he hopes I'm ok and he misses me how his new girl and him prolly wont work out. He tells me how beautiful I am and my issues are what make me so wonderful and beautiful. Then when I ask if I can get some things from his place (including our sons meds) he says he cant cause he has to go get his gf. I've been trying to get this stuff for 3 weeks. He fills me with words and memories to get me missing what we did have that was good then push me away. Then says in his mind I'll always be his. I told him what hes doing to this girl is wrong he cant play with people that way. He's with her but sending me messages just like the last girl. I love him but I'm not in love or love in a way of wanting. But he knows how to confuse me. Now with this new life I don't know what I'm doing I have NO freaking idea how to do this. I want my Chris he is so wonderful to me yes he drives me a little crazy sometimes but he doesn't make me feel crazy. He kinda makes me feel like I'm "Normal" with no issues with no disorders but then the ex comes in messes with my head and I get confused and flustered again and I pull away from chris. What do I do. I kbow this is all over the place but thats how my head is right now. What do I do? I can't cut him out because we have kids together and I wont do that to my boys. Oh and the last 4 months he quit drinking and promised our boys he wouldn't anymore. Almost made me think he could change.... But he drank right in front of my oldest who is almost 16 and he doesnt want to go over there anymore. He called my son shallow and put the blame on me..... Grrrrrr