need advice

i’m really struggling with something and could use some outside perspective. my partner cheated on me multiple times throughout my pregnancy. at the time, he was in the worst of his drug addiction, which played a big role in his actions, but i don’t think that excuses it entirely. he came clean to me himself, apologized, and promised it would never happen again. since then, he has been proving himself by staying clean, being fully committed to our family and doing everything he can to show that he’s changed. the problem is, no matter how much effort he’s putting in now, i still can’t shake what happened. i constantly think about it and it feels like i’m the only one stuck in this pain while he gets to move forward. i want to believe that he’s truly changed and that we can move past this, but i don’t know how to stop feeling this way. i don’t know how to let go of the betrayal and hurt. i’m exhausted from carrying these emotions, and i’m starting to wonder if our relationship is worth continuing if i can’t find a way to heal. has anyone been through something like this? how did you decide whether to stay and work through it or walk away? any advice would really help.