Sounds like your guy reacts to things going wrong in a very immature way and gets way too angry over way too little.

Sometimes a guy like that will be selective about who he throws major fits at based on who he thinks will tolerate him doing that. So after 9 years, he has concluded that he can throw fits like this at you. Unless this is how you want to live for the rest of your life, if you stay with this guy, you need to try re-training him. That would mean that you walk away from him when he starts throwing a fit. This is a lot like dealing with a child who throws tantrums.

He probably does know that he goes over the top, and that's why he gave you the $40. Him giving this sign of remorse can be kind of nice, but it still leaves you with the stress of having him wig out on you from time to time. I'll bet this sort of outburst happens rather frequently. It's no way to live. I'ld start refusing to tolerate it, if I were you. The more often he gets away with it, the more likely that he'll keep doing it.

Look how minor these incidents were that got him all nuts. What is he going to be like when it's something really big?

People prone to angry outbursts are typically selective about where and in front of whom they pull these tantrums. They often have the capacity for more self-control and will use it, IF they think they have to, or face losing an important relationship.