No no no my dear!!! It is not your fault at all! Obviously you are just telling one side of the story and I don't know this guy but it sounds like he really doesn't know how to handle his emotions and is very, very fickle. He probably shouldn't be in any sort of relationship until he can get his emotions under control and figure out why the heck he reacts this way. Of course if you are dating someone like this it will be a roller coaster. Someone like this shouldn't be in a relationship and they will make you feel guilty. These people aren't happy with themselves so naturally they will tell you they are not happy with you and make it seem like YOU are to blame. Which is far from the case because it sounds like you are a pretty empathetic person.

The best you can do is take yourself out of this relationship. If you want to continue talking to him, be a friend for him. Don't talk about relationships. Focus on yourself and focus on being the best possible person you can be. You can be happy when not in a relationship, and in fact, relationships that are unhealthy can be quite depressing. You definitely cannot change this person and make him who you want him to be. You can influence him...maybe help him get the help he needs or resources he needs. But life is way, WAY too short to put up with this BS and all the fights. Everyone on earth should deserve someone that is nice to them. There is no perfect relationship but the fighting in this one seems extreme. Give it time but until then focus on just yourself. And good luck