Long post about bf

We’ve been together for 3 years now. Started as long distance and moved in together late 2016 we’ve moved around a lot. From June 2017 to January of this year I was livin with him and his family in Florida. I moved back with my family end of January because his family was treating me badly. He was supposed to stay here as well but brought me and left 4 days later. He was then supposed to come back and live for our anniversary in March and didn’t. Said he’d come the week after that and didn’t and he was supposed to come last week before his birthday as well and cancelled the day before again. He never talks about wanting to marry me or anythjng like that and knows how important it is to me. He drove 2 and a half hours to go see a girl he barely knows even though I told him it made me uncomfortable he did it anyways. He talks to her and her friends a lot sometimes more than me and that makes me feel terrible and I told him. So I did what any concerned partner would do and signed into his social media accounts. I didn’t really find anything bad. He didn’t like that I was on his accounts and decided to change his passwords. I confronted him and eventually he gave me the new password which was actually a fake I tried it and told him. He then gave me the real one and it worked and it was fine. The next day he changed the passwords again. He says he has nothing to hide then why would he do that? I don’t think its wrong at all for partners to know each other’s sign ins. He’s known mine for a long time and I’ve known his but never had to use it until recently. He doesnt seem like he’s ever going to grow up or move here and I’m feeling so hopeless. Please share your thoughts and opinions with me