inhaling Styrofoam, being mentally paralyzed

I put Styrofoam in the oven without checking if its toxic first and inhaled a bunch of that sweet sweet toxin. My mouth fucking hurts cuz my mom's trying to get me off the medicine so I can go to school tomorrow(and not have the need to take it during the day). Which- excuse me? I'm already miserable at home, you think I'm gonna be better at school? I only took 3 days off. 

I talked to my therapist and she said that everyone has different pain tolerance and it took her 2 whole weeks to feel well enough to go to school. She also said that I should ask to stay home. I was going to do that until my mom came home and did her usual thing and asked me what I did(and I said basically nothing) then she complained that no one in this house is competent; which is TRUE but I don't want to hear it all the time. Then I freaked out when she told me to start doing shit to prepare for school tomorrow because the thought of going to school feeling like this?

 She was stressed and I know that but it made me feel like a burden when she recited all the stuff she had to do for the 100th time, including a lot of stuff she felt obligated to do but didn't technically have to do. I love her to death but jeez it didn't help at all when it came to asking to stay home. I was already worried she'd think I was overacting but now I'm super worried.