I trust you know this person well and that your experience is accurate.

However, you might find it useful to look up coping mechanisms in dealing with someone with OCPD. OCPD is extremely common and people with this personality disorder usually are extremely miserly and controlling. I’m not saying your person has this disorder. But from your story, the issues with money align closely enough that the tools people use in dealing with OCPD miserliness might help you. Or at the very least it might help you feel less alone in that experience.

I’m really sorry you are having to manage that and deal with this person. You sound like a very reasonable and empathetic person yourself. Please do something small and kind for yourself tomorrow. ❤️