You and your therapist are not in agreement about the best way to help you. She doesn’t want to get bogged down in the whys. You don’t want to follow her advice unless you have a better understanding of the “cause”. For some reason (probably a good one), the argument has become more important to you than getting on with getting better. It may be, for example, that new issues will emerge that are even more worrisome if you are successful with your studies. Talk with your therapist about whether if is safe for you to change.
Do work with your therapist to look at why you are arguing with each other and to come to agreement about how to proceed. As long as the two of you are in an argument (even if it is a polite one), your therapy will not progress.
I wish you well.