why am I such an idiot.

Amy • Wife ✨ Momma to a little girl & a little boy #3 on the way!
So here was the back story. He broke up with me a month ago. 
So my boyfriend has recently left me, two days ago, we just moved into a house two months ago. I've been having medical issues and haven't been feeling the best. I'm 30 weeks pregnant and have a high risk pregnancy and it's been one thing after another. And I come home to him telling me it's over, he doesn't love me anymore, I'm too selfish, I'm negative, and that there is nothing between us anymore. And that I need to be out of our house by the first. This isn't the first time he's left me all of a sudden, either. He was just sitting there with his legs crossed and not a single care in the world when he dumped me. So last night I was doing baby shower invites and texted his mother (who I was close too. We had a good relationship) asking her if she still wanted me to invite her and their family to the baby shower. I have heard no response. My ex dropped off our dog to me today along with a present from her and I texted her telling me thank you and how wonderful it was, and have heard nothing. My ex is throwing himself in multiple thousands of debt because he is breaking the lease on the house and I'm making him pay me back for the 3k that I had to put into the deposit. He is acting like he did nothing wrong and what he did is completely okay. 
So we ended up having sex and one thing led to another and we spent more and more time together and it seemed like everything was working out. We were communicating better, we were happy again. He even asked me to move in with him and his mom so we could be more of a family.  But then one day I just felt low. I remembered what he did. I got upset. All my future plans got shit on and it's been rough. Baby will be here in two weeks. So we started fighting. And with two days of fighting he completely switched up on me again. That we are not getting back together. That we are just co parents and nothing more. I know I'm an idiot for going back. But I just feel like I'm going crazy at this point because nothing is going right. I wanted him in the room and holding my hand. And now I don't even want him anywhere near me. I don't need the comments of oh you shouldn't have gone back. I thought I was going to marry him, he's the father of my child. I know I'm stupid for thinking things would change. But holy Shit. He is bipolar.