a little help deciding?

hey! i’ve got a bit of an issue i’d love to get some help with. a few weeks ago i broke up with my bf of almost four months after a big fight. everything was going fine except for me keeping thinking i messed up, and about a week later i was asked out by my friend of several months who’s two years my senior but treats me like an absolute queen and supports me through everything. problem is, my ex came back and wants to try again, and a part of me is going ‘it was just one small fight you overreacted and should pick things up and ditch the new guy, he treated you just as great’ but the other part of me is thinking that i left him for a reason and that i shouldn’t let him back in to my life. i don’t know if i overreacted or not because i had an emotionally abusive relationship in the past and the fight mightve brought back some memories i wanted to forget, but i have no idea what to do. Please no judgement! i only come asking for help, not to be ridiculed. thanks!