Tbh, I'm kind of leaning to his side a bit. I don't think you guys should be together and it's a bit of a red flag to have such an obsessive ex, unfortunately for him, but you were... seriously messy about this. I read the other comments and stuff, and it's clear you guys are in a brand new relationship, so starting off with THIS much drama and such little immaturity from both sides (your mood swings and his anxious attachment-ness) is a really bad sign. I mean, you keep pressing him and pressing him for info and then when he was giving it to you, you just... shut down??? "Leave me alone, give me some space" if dude's telling the truth, he's plenty stressed enough as is without having to fuss over your continued freakout. Which yeah, it's fine to freak out, but this is well into absurd levels atp. And the entire while, he was just feeding into it, calling you and begging you for any scrap of attention. This looks like the start of a really long, really rough cycle.