Resentment after abortion

My bf and I have only been together for 4 months. He has a 1 year old. I have a 4year old that is autistic with severe ADHD. I just found out that I'm pregnant and while I do not believe in abortions for myself my bf isn't ready to have a second child and I absolutely can not fathom the idea of me having a 2nd child without the support of the other parent. Not saying my bf would make me a single parent as he's an amazing dad to his daughter but the likely hood of our relationship staying stable is slim as we are still so new and currently live in separate households.

So we agree to have the abortion and it's scheduled

My dilemma. He wants to stay together and continue on our relationship but honestly I feel like I resent him already. I love being a mom and never in a million years would i think I'd be having an abortion at nearly 30. Both of us can financially afford this baby so going through with this is breaking my heart. He mentioned us being able to have kids later on down the line but the idea of him getting me pregnant again gives me like PTSD. It's like I feel like this abortion situation has stunted the growth in our relationship and suddenly I see no future with him and I don't know why my brain is processing it like this.