Looking for advice and constructive criticism

I’m going to try and make this post short and straight to the point as much as I can. I was in a 9 year relationship that ended bc I found out he had a secret relationship behind my back for months which started out when I was only 5 months postpartum with our 3rd and youngest. That was January of 2024. It wasn’t reality till about March bc I hid it from a lot of people bc I was in denial. Anywho I accepted the fact I will never take him back and he’s just a narcissistic that lacked all morals and very much was missing any sort of empathy towards other people. I felt free and I was finally out in the open as a single mom of 3 (all from him). Someone stumbled in my life early September and I told my self I wasn’t going to let it lead anywhere bc I just was in a long term relationship and I wanted to find my self again ofcourse that didn’t happen and after almost 2 months of talking to this said person everyday I finally allowed my self to hangout with them. We just connected and it felt safe/comfortable. He’s leaving for school in March for 3 months which I always knew about which wasn’t going to be an issue we were going to make it work. It was going great….until it wasn’t. I got an IUD right after my 3rd baby. I just found out I was pregnant on Wednesday totally shocked and dumbfounded. I went to him right away ofcourse and his reaction totally caught me off guard and quite frankly I’m still shocked about it. Basically saying how he’s been working so hard to finally be where he’s at and he’s making a huge step in his life to make something of himself and that he wasn’t coming back after school this and that. I had a abortion before my 1st baby and never truly have gotten over it mentally. I’ll still have dreams about that babe here and there. He totally ended things between us bc he had a son at a very young age with someone he barely knew and they tried to make the relationship work for so long and it ultimately hurt and crushed him and he said he wouldn’t put himself through that again considering we don’t truly know eachother or know if we mesh well together. I’m sure it’s a lot of past trauma but regardless he’s removed himself from the situation and basically said it’s my choice and he can’t force me to do anything but he’s leaving regardless. I have no idea what to do. I feel so lost and mixed with emotions and so mad and angry at my self for letting someone in so easily. I strongly believe everything happens for a reason but why this? I’m pregnant now with a completely different person than my older 3. That itself will cause a shit show with my family. Idek what the right choice is in this scenario. I just hate this stuck hollow empty feeling.