Menstral cut in high school bathroom

So I'm here in the bathroom at school waiting for everyone to leave so I can run out and clean my cup. I'm 16 and a sophomore and just started using a cup it's been a life changer except I have a heavy flow and have to change my cup every 4 hours. Also to make it worse the toilet won't flush and I duped my cup out in the toilet 🤦🏼‍♀️🤦🏼‍♀️🤦🏼‍♀️ .