I am so, so sorry to read what you are going through and hope you have some support in real life along with the support and help on here.
Right now it probably feels so overwhelming and impossible, but please, please believe people when they say that you CAN and you WILL get through this.
You will be missing, and almost like grieving, who you thought he was, who you hoped he was. He has shown you who he really is and, honestly, it is better to know now and start to re-build your own independent life as soon as possible. He never has been, and never will be, the man you thought he was.
As soon as you can, make a claim for Universal Credit (or tax credits and other benefits if they are in your area still). You can look on www.entitledto.co.uk to see what you might get. And also make a claim for child maintenance as soon as your baby is born.
It may also be worth seeing if you can get your name down for social housing - you are actually fleeing domestic abuse as he is being both financially and emotionally abusive.
Come back here for virtual support - many of us have been through similar and it really does get better. It's a blessing to know WHO he is now rather than years down the line, as those would have been stressful and unhappy years for you and your children. You have the opportunity of a much brighter future now without this arsehole grinding you down.