I really want to help him get better but he genuinely believes or convinces himself that it's my fault he gets angry. Sometimes it is (I am human) but sometimes he gets angry over fly away comments that other people wouldn't bat an eye at. I'm so torn. I know I should leave but I love him so much and he really is an amazing person when he isn't angry. But I know I shouldn't have to spend my life scared of speaking what's on my mind to my partner.
None of this is your fault. You are not responsible for his emotions or his reactions to anything. Like I stated in a previous post, this isn't "anger", not really. These rages that he seems to fly into aren't "recovery mood swings" or whatever. This is the cycle of domestic abuse. The thing about it is, those good times when he's being "amazing" to you, are also part of the cycle. It's all about establishing control over you and over the relationship.
http://www.domesticviolence.org/violence-wheel/
Red Flag- You've known this man for less than a year and you are already pregnant and practically living together.
Red Flag- You met while he was in rehab.
Red Flag- He blames his anger on you.
Red Flag- He is friends with people who think it is OK to degrade women.
Red Flag- He threatened to kill your unborn child because you tried to stand up for yourself.
I'm going to recommend a book- it's called "Why Does He Do That?" by Lundy Bancroft. You can pick up a used copy on Amazon. It's also available as an e-book. The patterns you are experiencing can be very hard to recognize when you're living that daily "walking on eggshells" existence, tiptoeing around, hoping nothing sets him off. Then those times when he's being "amazing" (which will get fewer and farther between the longer you're together) and you want to hold onto it forever and totally forget all the bad stuff.
Since you are pregnant, it means this man will have to be a part of your life on some level in the future. Please call 1-800-799-SAFE (7233) for help with legal issues resulting from custody/paternity matters and to help make a plan to keep yourself and your children safe from this man. He has his own place. He needs to go back there. You and your children are in real danger.