Should I let go of this relationship?

tabitha
been dating this guy for 6 months and i constantly had a problem with him and some girl who he said is just a crazy girl.  i find ongoing conversations in his phone from him and this other girl. he says that she's crazy and that he dont wanna talk to her but she dont seem to understand. now i look in his phone tonight when i came over and seen they were on the phone for almost an hour and again constantly texting. he telling her how good it felt taking a shit while they were on the phone and it felt good afterwards in the shower so im guessing he used the bathroom while on the phone with her. i also found they met up the other night without me knowing and from what someone tell me that he was out there for almost 3 hours with her. he told me that he was breaking communication off with her but she doesn't want to accept the fact that he wants nothing to do with her. she has hacked his accounts and he's perfectly fine with that as well and she talk controlling and he's a bit controlling as well but he's perfectlly fine with that as well. he said that she's forcing him to talk to her. i seen in text messages where they both said they ain't together, but from the text messages I don't know what to do call it. he changed his number twice but they still talked on whatsapp a while back after he would ignore her after she would make several accounts and she went crazy. i see different responses from what he was telling me. he said something to her about "im sorry i know how it feels to be ignored" they made up their problems. he constantly tells her he want nothing to do with her yet i still see texts. i seen messages where its proof they never sad sex yet because they argue to much. i see phone calls from him to her as well. they talk all day long whether its arguing or not. he said that there's no way to stop her or get rid of her. he even told her that she's complicated and that she won't let him go anywhere and she's forcing him to stay around. the girl stay an hour from our town. if she hasn't texted him in days he text her first. I have a son by another guy and he hates my baby father