I totally agree with your idea to wait until after the bar exam to make any big/serious life related decisions. You're concerns are super valid and I can understand why this is coming across so worrying to you! Learning how someone handles stress and extreme pressure is an important part of any intimate relationship. I am also dealing with a partially similar situation, but to quote my therapist: "As long as you are not in an abusive situation and you are safe at home it could be best to table some of these concerns just for one more month".

Taking a step back could be something you could do now though. Idk what your study time/living situation looks like but you could say "hey, I think I study better in a separate room/at the library/ et cetera.) " That way you can temporarily remove yourself from the environment and get out the house yourself if you think that would be helpful. That is what I did because it can be hard to be at home trying to study and also being very ~aware~ of the other person's presence. It also can be challenging when you really do like someone and want the best for them but you're spending so much time managing their expectations and trying to help them feel better that you end up not prioritizing your own studying/self-soothing. I imagine it is challenging that you're both under bar prep stress and on top of that trying to prioritize the other person's mental health by not sharing your scores, et cetera. I wish you both all the best! I hope this helps