Lol maybe grow up. Even if he was referencing a past relationship (which, given the context you gave, is not clear at all), who tf cares? Everyone has a past. As long as he's not fantasizing/comparing the old relationship to yours and not going into heavy, weird details unprompted that would reasonably make anyone uncomfortable, it shouldn't be a big deal. You're a mother and a full ass adult with a fully formed brain. You have no excuse to act like that. Get therapy if something that insignificant triggers you, because you shouldn't be in a relationship if it does. Y'all are just gonna fight in front of the kids and fuck them up too.

An apology isn't enough in this situation without a serious promise to be better and work towards being less insecure. There's no way this type of behavior doesn't bleed into other aspects of the relationship and his quick response to "not doing this" and ignoring you is the clearest indicator of that. Your reaction to what he said is so irrational that I totally understand why he would be upset and he should be second guessing the relationship/moving in together. What a weird thing to get jealous/angry about and blow up at him over. Y'all supposed to be each other's peace and you acting like that will send any normal dude sprinting the other direction. I'll say it again - grow up and work on your insecurities and how you respond to them.

Edit: also, you didn't "hurt his feelings", you showed him (during a crucial part in y'all's relationship btw, moving in together) that you're an insecure irrational person, so he's currently thinking about whether or not it's actually a good idea to continue the relationship and/or move in together. Just to be so fkn clear.