I'm not sure if I should leave him or not

When I got with my partner 5 years ago I noticed he was checking women out which didn't bother me that he was having a little look. I think he must of realised it doesn't bother me or he was just being rude I don't know why it changed but it did it went from little looks to "she's got a nice arse" directly saying that to me saying "her body is Making me to crazy" I said that hurts can you not do that he said yeah sorry then he started watching porn I found it on every device he had. I told him I didn't want that in my realtionship he sorry he won't do that again I didn't realise because me and my ex use to watch it together I said that's fine I don't like porn I told him my reason which is ( when I was younger I found porn DVDs I didn't know what they was I put it on and it come up with the title daddy and daughter later on as me and my sisters grew up my dad tried to act out what I had watched ealier on in my younger years so when people talk about porn I can't help but remember that moment and it scares me to think people act on things that are just for entertainment) I would like it to stay out of our relationship. He hasn't been on it since I'm greatful for that but the staring at women and commenting on how he wants to fuck them how there body makes him hard makes me feel like a fat potato next to him. The worst of all he gets worse when I'm pregnant I have a child with him when I was pregnant with her he use to call me fat and say I don't make an effort with my self anymore ( I was sick all through my pregnancy I was on crutches because spd plus I was in and out of hospital which he told me was wasting his time because he could be working rather than stuck up the hospital with me) anyway his parents had a party for there anniversary so we went I was 6 months pregnant I brought a beautiful dress to make me look slimmer for him so my bump and bits didn't look big. He didn't comment on how I looked after I got ready. We went to the party I didn't know anyone there but his parents and sister they done there own thing he left me sitting on a table all night by my self he got really drunk and the Times he did come over he sat there looking past me doing pig grunting nosies because of a women who was much thinner than me because she's not pregnant. And was wearing a lot less clothes than I was I just thought how disrespectful he was being I was sat there pregnant alone and he was just being rude. I'm pregnant again I'm 8 months pregnant now and his doing it all again it's getting worse his telling me he can't help but look at fit women because I've put weight on we haven't had sex in 4 months I'm so convinced his cheating he laughs when I say that. I don't think his being nice or fair I don't know what to do anymore I'm so drained with trying to look nice for him and he still tells me I'm fat and not good enough he told me he don't like going out in public with me I asked why he didn't answer it. Is he embarrassed because I'm pregnant and big? Any advise please?