Period started and I can’t get to a bathroom!! HELP ME

I ride the school bus even though I’m a senior and my period just started!! I wasn’t expecting it so I wasn’t wearing anything to protect my undies & I don’t know what to do. I asked the driver to turn around and take me back home but she wouldn’t do it. I don’t get off of the bus for another hour and my flow is HEAVY!! It’s not like I can change it in the seat because people sit everywhere around me. I don’t know what to do because it’s starting to leak through and everyone’s going to see it 😭😭 I really need to know what to do right now because I’m in a REALLY BAD SITUATION