What should I do?

I wanna tell him if he doesn’t change his act I’ll leave. But I hate hurting feelings so.

He’s just so aggressive towards me now. He has anger problems and he gets angry so easily, from everything. He has road rage, he literally complains about everyone even if they do one little thing wrong, there has never been a time I’ve been in the car with him that he hasn’t complained (ever since he started getting worse that is) like he complains every 10 mins. He’s broken his radio by punching it because someone “pissed him off” when he was driving. If his family members say he’s doing something wrong he gets mad.

I was messing around with him (tickling him) he does it to me a lot so why not get him back. And he kept punching my arm, and now it has a small bruise.

Idk. He’s just turned from this super caring guy that would do cute things for me all the time. To this guy that I don’t know anymore. He’s aggressive, has anger problems, doesn’t do anything for me anymore (he shows his love by buying me things, so I don’t tell him what I want anymore) (I loved it when he wrote cute little notes and stuff. And he doesn’t do it anymore. Even when I ask him)

Idk what do I do? I’m trying to be an adult and not do childish things anymore so I can better myself. I’ve tried telling him what he’s become and he gets better for a day and goes back.