new relationship

What does it mean when I constantly have nightmares about my boyfriend and his ex baby mama getting back together? Recently she's been texting him non stop because she's jealous and he always tells me not to worry because she cheated and he has no feeling for her at all and he always talks about me moving in with him and getting married and start our own family and we've been hanging out everyday and sleeping over each other houses everyday but I feel like lately he's been different and I don't know if it's because he wants her back too or whatever because this has happened to me before, (my ex) where he says he doesn't want the baby momma but as soon as she gets jealous she wants him back he falls for it and then breaks up with me and realizes that was a mistake and he wanted to use me for a car, money, and baby sitter because he was a shitty dad (still is). But anyways I really like this new guy, we met each other's parents, his son loves me! And my bf wants to say I love you to me already and I think he's scared of losing me because all of his exs cheated on him and he thinks even when I leave to the store I really mean I'm gonna go cheat on him even though I'm not! And I wanna say I love him but I'm just so scared of him not being over the baby momma😢