In high school, I had experience with people taking photos/ videos of me and I can 100% understand how you feel right now.
If it's a school bus then all you can do is tell your school, and a teacher you trust so they can be talked to, there are usually cameras on all buses, if you like you can email the bus company you take if it isn't a school bus.
As none of what they did was illegal, I'm afraid there's not much more than that that can be done.
You're not crazy for assuming it was you, teenagers suck at being subtle, however, all I can suggest is you try not to take it to heart. They will go after anyone, and it isn't a reflection of you.
I completely sympathise with your situation and if you need anything feel free to PM me <3