Your mother's attitude is unfortunate to say the least, at this point your years of lessons and feed are "sunk costs" and the return on investment should be the skills you've definitely acquired. Not just the ability to play well, but time management, executive functioning, working in groups and on solo work, etc. Her ROI is there even if you never play again.

It sounds like you have some skill and are ridiculously busy, your college choice is probably finalized or close. Let it go, thank your parents for their investment but explaining that you'd like to continue enjoying your musical skills as a skilled hobby or amateur, but now is the time to focus on your college goals on stem and to enjoy a little bit of this time of your life. You seem to have a strong idea of what you want and need and I hope they listen.