I want to keep my routine when my mom makes plans assuming that I don't have any
That feels inconsiderate of her, does she do this often?
Yes, I'm to the point where I want to end our relationship
If your mom keeps making plans and wants you to do them without asking, you should tell her that you have plans. Have a conversation with her about her behavior and how she can potentially fix it.
We are planning to stop talking because of this.
I don't think it should go to that point as it can easily be resolved if you just talk with her calmly and sincerely and I am sure she'll understand. Making plans with you is a sign of love and you should still appreciate that.