Difficult times

I guess when you first have a break up you can not possibly believe that the person you loved most in the world would become your enemy. It is unimaginable that that most special person would think nothing of trying to hurt you emotionally whenever they can.
Michael and I are not in a good place right now. I do not understand why it is this way but it is. I am but a pebble in his shoe. I guess I sort of get it...I mean I hurt him, I left, but he reassurred me we would remain friends and that we would always put our children first.
If he is so in love, and so happy and so committed to her then why does he have to treat me so badly?
Lots of people say that this happens, but I really did not believe that this would happen to us. Dream world? Maybe....
But what do I do? I didn't push the house or the contents thing. It is just stuff and money and I was not going to get into that. I gave in to the no phone calls from the children each night that they are away from me. I was seeing them in the morning most days so that was ok. But now, now it is about the children. Now it is about their wellbeing and welfare and I will not back down.
I have always given in to most things. Why? Well when they were not realy important I never felt the need to push. I wanted him to be happy so I always agreed on him buying the things he wanted. He got to go on rides and spent lots of time on his bike and computers. It was never an issue. I gave and gave out of love.
So is it now that I pay for being a giver? Does he now think that I will just do his bidding and bend to the pressure? Am I seen by him to be such a pathetic creature that he feels nothing about trying to manipulate and walk all over me?
The last thing I want is to have a messy time with everything. In the end nobody wins. But I cannot be the one who gives in all the time. I cannot be the one who is expected to just accept his bidding. Not when it is about my children and their welfare.
The rose coloured glasses are really off.