Single and he's dating someone else

My partner and I planned baby #2 and had the most wonderful family holiday in May which is what we needed as we had been having a few rough patches but after 6 1/2 years together we always came out the other end, August bank holiday he went out and didn't come home until very late so I locked the door and told him to go to his parents he said if I did that he wouldn't come back - ( it was extreme but I was having a bad day and had work the next morning and with Him in no fit state I was furious) I admit I was very wrong and awful towards him for the next 24 hrs after this happens. 
I'm pregnant we have a 4 year old I took it as an empty threat- fast forward 13weeks and I'm still single he's actually seeing someone and started  to date them a week after he left me - I do know this is the only true thing since we finished as she met him like the rest of our mutual friends the same night. I am 22 weeks pregnant and very hurt very sad and I miss him dearly, how can he not miss me? How can he move on so fast? This woman is 30 years older has no kids and he thinks she's Jesus and I'm the devil, I am nothing but a chore to him and I'm now having more bad days than good, I feel like my whole life is on hold wondering will he ever be sorry. We had life plans together how can he turn his back on his family , he only ever texts to ask to speak to  our daughter and sees her once an week. He literally has cut me out of his life after 2 years of being friends then being together for as long as we were. 
I'm a broken person and I feel like I have no where to turn all we do is argue I've cut contact to I no longer bother him, cry to him or anything and he seems so happy with it 😢😢😢😢😢😢