Bf said he would “k*ll himself” if we had anymore kids and now I’m pregnant I don’t even wanna tell him🤦‍♀️

What should I do? my kids dad and I have 2 kids together. After we had our second I told him I still wanted 2 more kids eventually (I’ve always wanted 4 kids) obviously not any time soon just eventually. He told me he absolutely was done having kids and that 2 was plenty enough for him and said he would probably “k*ll himself” if we had anymore. I don’t think he would genuinely k*ll himself that was just his very messed up way of over-exaggerating how much he DOESNT want anymore kids. He said that maybe 2ish months ago and last weekend I found out I’m pregnant. I haven’t even told him about it because I know he’s gonna be so upset which it’s his fault just as much as it is mine. I myself feel very unprepared because I wasn’t expecting this so soon either as our 2nd isn’t even a year old but again I want 4 kids so to me this isn’t the end of the world but he genuinely doesn’t want anymore and has made it clear. What should I do? We were using condoms/pull out method regularly but nothing is 100% and we must have had a slip up somewhere for this to have happened, there’s nothing that can be done now so im not sure what I should do or when/how I should tell him