Why is my ex so horrible to me, and giving mixed signals :(?

Me and my ex got on really well, then he finished with me and hurt me so much, we got back together, but I was so hurt I needed time and explained to him that I still have feelings for him but need time to think, he went mad and started calling me ugly, and other things like a sl+g, I was so hurt, and upset and he texted saying 'soz' he came to see me 3days after I gave birth to our child and he said I don't love you and I don't fancy you anymore, I was in tears, he told me he said it to be because he didn't think I cared, I do miss him, I just don't understand why he is so horrible, I've offered to work things out slowly, and he said no, and said he finished with me because I have a sh�t personality and other horrible stuff, and then he says to me he wants me to decide whether I want to be with him or not cause he might of met someone else, then when I've asked him if he has, he said no he can't meet anyone else because he still loves me, so I don't get it, he apologised for what he said when he came to see me, and when I explained that the things he says hurts he says crocodile tears, he goes out every weekend, and only comes and sees me and the baby when he feels like it, one minute he's saying he wants to work things out and the next he will ignore me and be nasty and not realise it, he said he will visit next weekend with the baby's xmas presents I don't want to see him so told him I won't be there, but he's welcome to go to my mums house to see the baby, he said I'm not coming if your not there, you said you want to work things out I expect you to be there, last night I told him I feel like he hates me, and he said no I love you I want to work with u, and today he's pushing me away again, my baby will always come first, I just don't understand him, what to say to him, and what's going through his head :/