Struggling to Take Painkillers with OCD

a problem i have always had with my OCD is that i have a hard time taking any sort of medicine that isn't my daily cocktail of pills i down in the morning. anytime i try to take something apart from that, my brain says "no that's bad no that's bad no that's bad no that's bad bad bad bad bad bad bad bad bad" etc you get the point. the frequency of times i'm in pain is increasing and i'm at a loss. i struggle to take painkillers. my mother does not understand this and gives me a lot of grief for it. additionally, if i actually did manage to take painkillers whenever i needed them, we would run out within a week. i don't think my mother understands how often i am hurting and/or uncomfortable. i just don't know what to do anymore