DP & I been together 4 ½ Years, have a DD (10m) and I have DS (13) from previous relationship.
Don't really know where to start; I don't really know how I ended up like this. When we first got together we were a very passionate couple, I had never met anyone I was that compatible with on so many levels. The sex was good, we got on brilliantly both happy etc.
There were some issues in the first few weeks as I suspected he was still lingering around his ex before we became serious (coming up with the most ridiculous stories to hide it). I got pregnant in the 1st month or so and after talking it through, although it helped us make the decision to have a serious relationship, we decided to terminate. Except he left me to deal with it by myself, and later threw it in my face and said he thought I had lied and never really had the termination! The fact I was bed ridden for a few days with some awful problems afterwards conveniently forgotten...
I think this left me insecure as I became really quite irrational, drinking a bit too much, starting arguments over nothing and getting angry and jealous where I hadn't been before. I was also quite destructive and my go-to stress relief during a row was to throw/break things! mostly his stuff but mine too. I was violent and aggressive. Things came to a head and got really bad and I realised I was going to lose him and potentially the best relationship I'd ever had. So I bucked up my ideas and stopped behaving like that, I knew it wasn't fair or right and I was destroying things. I'm not perfect; I still get mad and argue like everyone else but I have stopped that aggressive unreasonable stuff from before - this was about 3 years ago!
Then we went through a phase of him going totally off sex, all the affection died and it was breaking my heart that we seemed to be living separate lives. It may have been caused by me to start with, but after I changed and went back to 'normal' he became worse iyswim? So things were difficult but we got past it and were rubbing along ok, not the loved up couple we were but still in love and wanted to make it work. I always knew he drank more than what I thought was 'normal' (must find a better word than that!) but it didn't cause a massive problem so I just tried to discourage it.
When I became pregnant with DD he gradually started to change and now my life is unbearable, I can't see a way back to happiness from this misery and TBH don't even know if I want to anymore. His drinking and behaviour is appalling, most of the time he doesn't care as he doesn't remember what he has done or has convinced himself that I must have done something to make him that way. He is just mental, in the same sentence he has asked if I want a cuppa and when I said no thanks called me a bitch, slapper, whore etc! WTAF??!! At 5 months pregnant, it was my 30th and he had me round the throat screaming he wished he'd kicked the baby out when he had the chance. He has spat on me, called me a fat cow (the day after I gave birth), says disgusting insulting things about being intimate with me, tells me I smell etc! He has headbutted me and slapped me once or twice. He is just vile when he wants and really knows how to hurt me, emotionally and physically.
At the start I was violent towards him (threw stuff at him, slapped and kicked) when I was being insecure after the termination so I don't really feel justified in complaining about these things. I was wrong and I stopped behaving like that, not an excuse but just want him to stop now too. And I think it's fair that his level is escalating beyond where mine ever went.
He is already using our daughter as a weapon, tells her I am a shit mummy, I don't look after her properly etc. This from a man who spilled a pint of cider on her at 6 months when pissed and tried to pretend he hadn't! When I made him admit it I got the bollocking for 'just going out of my way to start an argument'! He has done other stupid man-mistakes where DD is concerned which I have never held against him as he is learning but he tells my baby girl I am an evil useless bitch 
He never plays with her, avoids looking after her and is very tit-for-tat (i.e. left her in a dirty nappy when I was in the bath because he changed the last one) Despite how much I HATE him some days I have never done/said anything like that about him to her and wouldn't.
He has also come to resent my DS who now avoids home as much as he can and stays with his dad instead. DP has verbally abused DS months ago and was showing signs of aggression towards him, TBH, I went mental and said if he ever did it again we would be over. He realised he had crossed the line and that stopped, then he did it again last night! DP was calling me names, trying to stir up a row and when DS said that's not very nice, leave my mum alone DP started yelling 'fuck off and mind your own business you little shit' etc. I honestly don't know how I kept my temper in check. He is always arguing with DS and I have seen him try to find things to tell him off for. He bullies him - he is 35 FFs I know teenagers are difficult but he is worse!
I feel like it's over and don't really know what to do. I have told him things are over before, he just says I'm not going anywhere, I love you we're just having a hard time etc. I have said this is more than that, he is destroying our family and it is his turn to change or lose everything but nothing works, he just goes back to being the same nasty bastard night after night. He sleeps on the sofa and as soon as the kids are in bed I avoid him, go to bed myself anywhere as long as it is in a different room to him.
To make matters worse (expects massive flaming) an ex has been in touch, one I never really got over. He is telling me things like I am beautiful, sexy, he would give anything for us to be together etc. It is v flattering and the only thing I have smiled about in months but upsets me too because my DP obviously doesn't think these things about me anymore, and I really didn't think anyone ever would. I am due to attend a reunion in a few months and I am worried that with all the emotional fuckwittery from DP and after a few drinks I will end up doing something stupid and have a drunken grope with the ex that will be there. I am already thinking like that which is bad enough. I just crave someone who is nice to me. The recent thing with the ExP is something and nothing really, it has just opened my eyes that maybe not everything DP thinks about me is true.
Sorry for the LONG rant I just don't know what to do. I think I want this to be over but deep down I know we made each other happy once and I just wish there was a way back to that ? is there?