Most Helpful Guy
Why did he leave and why is he bitter, twisted, and angry towards you?
Most Helpful Girl
Sounds like he might still have feelings towards you and that's why he is so angry. Normally people only get that angry if they have feelings or the other person did something hurtful.
The baby part can be a very difficult decision to make. If he says he doesn't want it now you may have to decide whether you feel the same or whether you could cope bringing up a baby on your own. If you do have the baby you may need to be prepared for him to change his mind, maybe in years to come.
Some people don't deal well with being on their own and this maybe why he has decided to have a new girlfriend so quickly. His new girlfriend may also have doubts when it comes to you if he is upset. She may get jealous and get angry at him for being civil to you.