[Eternal]

Ignoring you isn't a healthy part of a relationship and neither is hacking into his accounts. I think you both need to take some time to cool off, then sit him down in person and try and communicate. It seems to me that you guys are having trouble communicating, and that's a key element in staying together and being able to work through any issues.
Ade is right that some people like to talk things out right away, while others like to have some space first to cool off, and then talk about it. It sounds like he's the type who wants space, so you need to try and respect that even if he did something that really upset you. Trying to talk things out when either of you are upset can very likely make the situation worse. Instead, try going for a run, taking a hot shower, or doing something creative to get your emotions out. Once you feel more level-headed, that's when you should try and find a compromise together and a resolution.
I understand you don't feel bad about locking him out of his accounts, but that really isn't a good way to handle your emotions. It will make you feel better temporarily, but at what cost? It may just push you both further away and cause more problems within your relationship. That's why it's best to try and not act out without thinking, and to find activities to cool down. Fights are normal in relationships, but they should never cause either of you to do mean things to each other.