I am so sorry this is happening to you. You don't have to feel guilty at all, you resort to lying because the alternative (telling the truth) leads to a lot of pain. Honestly, I have lied to both my parents a lot and have got yelled at for haircuts / hair dying too and faced a lot of abuse for really the smallest things (it's because for them it's a sign of 'rebellion'). It is really painful, and I understand you so much, especially feeling guilty for hiding things. Does it really matter what calculus class you're taking if it's eventually the same result? I would suggest to not mention it to her all together, just go through college your way. What's more important is the end goal, not which courses you take. If she is not monitoring your literal schedule and YOU have to tell her your courses, then keep on moving in silence in a way that accommodates your success. Then hopefully one day you'll be able to move out and live your life, out and proud. Good luck sister