I don't know what to make of this. But I do know that relationships where one person gets angry at the drop of a hat, and then one minute later is like "I love you I want to be with you FOREVER".. that's just creepy.
Look, no matter how stupid and offensive your joke was, (it'd help to know what it was) his reaction is still suspicious to me.
He should be able to say "I didn't like that joke, because it made me feel like.. [whatever his valid reason is]", he shouldn't get angry and be like "you stupid bitch! I want to break up with you!" and then right after be like "I love you forever, isn't love great?"
seriously, a relationship which fluctuates between extreme happiness and extreme anger, between stay-forever and breaking-up, is not a healthy one. Especially if rudeness and anger are involved in fighting, it's not a good sign.
Now, maybe i'm over-analysing this. But think about it.