Any Advice!?

So I have been best friends with this guy for over a year and we always liked each other and so we started dating in October. This relationship feels different from all my rest. I actually feel comfortable and in love completely and I can't even explain how I feel towards him. This relationship has felt very real and the best I have ever had. He pulled me out of depression and stayed with me through some dark times. We do argue a lot, but that's not the biggest issue. But recently he addmited to being in a group call on Skype playing truth or dare with a bunch of people and asked everyone for nudes. So I wanted his Skype password cause I wanted to see for myself what he was doing. He stalled for a while saying a bunch of crap and taking forever just to give me his 8 letter password. So idk if he deleted chats or not. Anyway he had also said "Just so you know I do talk to a lot of girls." And "Don't get upset by what I say to them cause a lot of them are just depressed girls so I can't be mean." And I don't know what he meant by that so was he trying to admit to flirting!? I have no clue. Also he never admits he is wrong and sometimes he makes me seem and feel like I'm in the wrong. He says I technically cheated on him so I should forgive him for all of this and that is the whole reason he did it. By that he means the guy I dated before him. He says that the fact that I knew that he liked me and I liked him when I started dating this other guy when me and him we're just freinds was Kinda like cheating cause we were basically in an unofficial relationship. He wasn't even upset with the fact I dated the guy he was upset with the fact I sent the guy one nude before. And he never considered it cheating then but suddenly considers it cheating now but I'm pretty sure that dose not even come close to counting as cheating. And sometimes his explanations/stories change or don't make sense. So I feel like I can't believe him sometimes. He has also said in this particular argument "I don't even tell other people I have a camera so they don't ask for pictures of me. Because I know if I'm tired I just might do it." And recently I've found it hard to trust him and believe him and sometimes things just don't feel the same and I feel distant. He spends more time on his video games than he dose talking to me. And sometimes when we do talk he seems very tired or unhappy and sometimes he sounds happy and cute. (We are currently in a LDR) I almost broke up with him after he had lost my trust but he ended up calling me crying and saying he was going to kill himself if I did. Then I threatened to tell his sister and he stopped but still cried and said sorry and ect. So I decided to not dump him but to just try to forget about it cause I really like him. But I can't stop thinking about this. What should i do!? Any advice? Also I'll add pictures of some of our chat so you can see for yourself some things he said.