Having uti as an high schooler killing me (mostly rant)

Tomorrow is my first day back to school and I am genuinely spiraling and overthinking this so bad.
For context, i live in Indonesia. Unlike Western schools, every single Monday, schools here hold this mandatory morning assembly called "Upacara Senin". We have to stand in neat rows out in the school yard for basically two hours straight. no moving, no sitting down, just listening to long speeches...

and this is what im worried: I currently have a UTI, which means I need to pee every 30-60 minutes. On top of that, if i try to hold it in even for a little bit, my stomach instantly starts cramping up and my whole body gets so sore and achy. The physical pain makes holding it impossible, which is why i'm so terrified of being stuck in the middle of a ceremony.

im also shy, the thought of asking a teacher for permission to leave the lines gives me massive anxiety. to make matters so much worse, the student restrooms are located directly in front of the school yard. If i leave the assembly to go there, i will literally have to walk right in front of the entire school (Ther's alternative tho, the teacher's restroom is behind the rows, but I don't know if I'm allowed to use it).

I WANT TO KMS, I FEEL SO MISERABLE What should i even do? I talked to my mom about it, and she straight up suggested I wear an adult diaper, I don't want to wear diaper at my big age...

Should i just force myself to be brave and ask my teacher for permission to use the teacher restroom? Has anyone else survived a UTI at school? help