A Secret Guilt

I've been taking care of my partner since they got sick last year. They rely on me for everything, from daily tasks to emotional support. Lately, I’ve found myself indulging in a fantasy where I’m their strict caregiver, issuing commands and setting boundaries as if it were natural. It’s a weird power dynamic that both excites and terrifies me. Is this normal? Am I exploiting them somehow? What should I do?