Struggling with Boundaries and Disrespectful Mother

my mom and i don’t have the best relationship, nor does she respect my boundaries. i’ve had to ask for space today because i accidentally slept through my alarm for therapy since i decided to take a nap because i dont really sleep often anymore due to insomnia. she told me she was “ extremely disappointed and i was being disrespectful “. despite the fact i contacted my therapist after and they were fine with it and completely understood. my mother on the other hand decided to wait until my boyfriend left and come down and try to talk to me even after i asked her very politely for space using as many i statements as i could. she doesn’t respect my boundaries or feelings.