His life hasn't changed since we had a baby. He sleeps in, takes long baths, plays games on the PC for hours every day, eats and drinks when he wants. He even spent 10 hours out drinking with colleagues at his end of work Christmas party

His behavior is appalling and extremely selfish... unfortunately, it sounds like this is who he is as a person.

I know the old addage is 'Love is blind' but at what point did you look at this "PC gaming, Youtube binging, heavy drinking, verbally abusive, belittling you constantly, refuses to feed, clean, walk his dog" Asshole and think.... "Husband and Father Material!!"

I am glad you have gotten up the courage to finally leave this dropkick of a human being.. but please work on yourself too! Planning to have a child with someone you know is deeply flawed does not show good judgement - get some help in learning to recognize red flags and advocate for yourself in future relationships or you may find yourself in a very similar situation further down the road.

Best of luck OP.