I have sleep paralysis fairly regularly; like you, it usually comes and goes in bouts - I will have it every night for a couple of weeks, then nothing for a few months.

My most recent episode did involve therapy, although not with 'my' therapist, just a generic 'therapist' (I couldn't see their face). I think my nightmare absolutely was about therapy; about the relationship I have with my therapist. It also played on fears I have outside of therapy as well but these are fears that are brought into sharp focus during therapy. Personally I would think the fact your mind chose therapy as the setting is relevant. It certainly is for me anyway. I discussed it with T who helped me to untangle what it was about and how I felt. I find talking about it and understanding it is the best way to stop the dreams from recurring as often.