Big Question... diff scenarios than most... a little advice? You know I'll weigh this outcome of this..... nvm?

I know it's her body and I know I have no choice in it but, me and my girlfriend just split up and we were "trying to fix things" and, she told me, her chest hurt, her stomach felt bigger and and and. I'm no idiot but for some reason I decided to block that out and try and help find out what else. We have now split again and she has straight up told me... she's pregnant... it's mine... and she IS having an abortion. I have no choice in it. And yeah, I know I don't. I have 3 boys and another child would stretch things but... that's my child... How do you deal with this? Because.... I'm not. I want to be mad, I want to force something to happen but that's not my right. As far as whose body it's in and who has to go through the most, and legally. So any opinions, stances, desires, dreams... they're gone. They're gone. I am losing what would be mu child. What do I do? I can think of a few things but none that would do anybody any good. I'm not trying to get a "you're shallow", and "she goes through more.. much more than I have to. Granted. But I have3 boys of my own and there's a strain there, yes, but I can work later times and figure out how to fix whatever. I understand that but I have a baby right now, call it whatever stage of formation it has arrived at yet but if you leave the child alone.... there's a baby.And.... she has every right to.... but she's killing my baby! What do I do