Just Can't Help Myself

Ended it with my ex last month after catching them cheating. Thought I was over it, but then last night while watching a workout video alone in the gym, I couldn’t resist touching myself. It felt wrong to do something like that when thinking of someone else. But damn, it also felt good. Now I'm questioning everything. Am I just moving on faster than I thought? Or am I still really messed up about what happened with my ex? What’s normal here?