How to forgive my fiancé

So last night my fiancé and I had sex and he knows to pull out but he didn’t. We have a 4 month old and our sex life has gone way down which is to be expected. I’m feeling super overwhelmed and violated because he knows to pull out. Without me saying anything he apologized after the incident and knew what he did was wrong but that doesn’t really fix it. He told me he was about to cum and I said “pull out” and he said “no”.

Here’s the real issue. I’m very extra sensitive about this because I had an abortion which I regretted May 2020. It tore me apart. I think of that baby every day and have been diagnosed with PTSD. I almost ended my life over it and saw having another baby as the only option to get through it. So here she is, beautiful, perfect, my little angel. Anyway, since this is a trigger for me, plan B is also a trigger for me. I’m not against plan b at all but for me it just feels like I’m saying no to another child that could possibly be. So plan b is out of the question for me. All there is to do is sit and wait to see if I’m pregnant and I’m praying I’m not. But even this makes me feel awful and brings back horrible memories. I believe all babies are precious gifts. I’m just torn, hurt, and scared. I guess I’m just here to ask how to forgive my fiancé. He’s apologized profusely since but it doesn’t cut it. He lived the nightmare with me and even fought knives out of my hands when I couldn’t live with myself and I’m heartbroken he’d so stupidly do this again. To me it feels like he’s jeopardizing my mental health for a nut.

Side note: I’m also breastfeeding and worked hard at it to exclusively breastfeed and shed a lot of tears to get where I am and plan B is known to decrease milk supply. So that’s another reason I don’t want to take it. I also don’t take birth control because I wanted to use the NFP method but clearly that’s not working.