RS mentioned a point that I forgot, yes it does take two of you to work through this, and that does include addressing his issues. Before my bf cheated I would be the last person to accept I needed counselling. I have so much of a belief that I have to appear to be perfect, I would never have gone to counselling. But three days after I found out about the one night stand, I was a mess and didn't know what else I could do.

If you were to suggest counselling to him, try not to make it so that you are accusing him of being crazy. Maybe "I'm so sorry for how much I've hurt you. I really want to help you feel better and I'll do whatever I can. But I know that it might be hard to talk to me about some things because I've caused this". Or if it's couple's counselling phrase it as you asking him to help you find out how to be a better gf. I'm sure he does need help and sometimes it's hard to talk to friends about this because they don't understand how cheating can not be a dealbreaker. I told one friend and while she was supportive she was just at a loss for words.

Oh I just noticed the suicidal thoughts point! After the disclosure that my bf cheated was the first time I ever considered suicide. I just hurt in a way I didn't know existed and wanted it to go away. If he has a tendency towards those feelings, I can't help but think that this might be a dangerous time for him. I don't want to scare you, but just keep an eye on things