First off are you even comfortable playing the domme role as needed? Second he’s not Dom overall if he’s wanting you to domme him as well. He is a switch and in turn is assuming you to be a switch as well. Have you both discussed what denotes when one of you is one role over the other. Are there certain boundaries to it all? Degrading and punishment are all usually specific to each dynamic, persons involved, and expectations. Meaning we couldn’t know what fits you two best knowing nothing about you two. This is all stuff that should have been discussed during negotiations between you both. Same for the rewards. If your both lacking the experience in this field then maybe it’s not the best of fits. It might be worth finding a mentor. Not sure if your dynamic is online or irl but I’d suggest finding a mentor for you both who is whatever format your dynamic is.
It’s hard for some subs to ever be dominant and someone just assuming their sub partner can switch to Dom is very shallow thinking.
It sounds like you two need to take some clothes on sit down discussion time and hash all this out. Who knows you better than yourself. And same for him. Open honest discussion is what builds the foundation for a solid dynamic.
Nope this helps