AIO for not wanting to be around kids, especially my boyfriends family?

Putting a warning for miscarriage

I want to start by saying, ive always wanted kids. Im a typical woman who absolutely loves them, even when I was a kid I wondered what it would be like to have my own family. Ive been in a relationship for almost 2 years now, and on my birthday last September my bf and I did the deed, we weren't careful cause we've never had any issues at all.

I had no clue that my boyfriend had gotten me pregnant. I noticed my skin clearing up and some changes in my body, and literally the same day that I began to wonder if I was, I started pouring blood in the middle of work. The situation was extremely traumatic considering i had no clue what was happening to my body. My boyfriend was out of town and asleep because he was working nights, within 10 minutes, blood was soaked all the way down to my knees, I RAN out of work crying and freaking out. Went to the ER, and of course was told the unfortunate news that no woman wants to hear, i was alone in the room with nobody by my side while learning that i lost the one thing ive always wanted. It was a really rough time. I stayed out of work for a week, but when I came back the ladies at work already knew what happened, and I was just a completely different person after coming back.

I was only 6 weeks, and didnt even know about it prior, so I gaslit myself into thinking i didnt deserve to be so tore up. However, ever since that happened, its extremely hard for me to be around babies. The only one im ever around is my nephew, and sometimes I do just look at him and cry. My issue now is that my boyfriend has been sexual with one of his distant cousins, (this was years and years ago when they were maybe 11) ive always had some deep rooted jealousy since learning this and dont really like being around her much, mostly because she just glares at me and doesn't speak, assuming because of their past. But her and her boyfriend just had a baby.

My boyfriends grandma immediately came to us showing us tons of pictures, bragging about how no baby on earth is as beautiful as hers, literally went on about it for 20 minutes until I couldn't take it anymore. Ive had to mute her posts on facebook, because seeing her baby pictures will ruin my day. Ive avoided family gatherings because im not sure i can handle everyone talking about the baby and making it such a big deal. It may be selfish, but all I can think about is how that should've been us. Her and her boyfriend weren't even together but maybe 2-3 months when she got pregnant.

My boyfriend said that he talked to his other cousin about it (this girls brother, who my bf is super close with, also has a baby) and him and his wife apparently said that they completely understood why its hard for me to be around them. With 1 year coming up, im an emotional mess and im not sure if im overreacting. But Im anxious as hell knowing that a halloween party is coming up too and im most likely going to be forced to be around his family. Idk how to handle it. Every single woman in the family has a kid, even the women younger than me and im only 24. I know my boyfriend will say im overreacting if I dont show up, and I dont want to be the one who misses out just because of my own personal feelings. But I just really need to know if im overreacting or not?