Me F 18 bf 20M texted his old crush and i can’t get over it what can I do?

Me and my bf are dating for 1 year now and six months ago the night before we were gonna meet up he texted his old crush ,he says he was feeling bad and wanted to talk to someone and he chose her there wasn't anything inappropriate the conversation is just how life sucks ( economic problems)and the next day he told me he texted her (by the time i didn't know he had a crush on her he just told me she was in his old friend group)and not only that but he used to make a lot of inappropriate comments about his ex and some characters , he doesn't think he's doing something bad and he forgots about what he just told me , all these things make me feel unworthy ,aslo im a really jealous and obsessive gf and this doesn't help at all and i cant over the fist part please help me