I want to move on in life

I'm about to be a senior in high school and I don't want to carry this into the rest of my life. It started freshman year and has slowly gotten worse since then. I used to just wash my hands and be done with it, but now I have to shower at least 3 times before I feel clean. It's not everyone — only certain people I don't like or find annoying trigger it. It's not really about germs; I know that logically. Even when I know I didn't actually touch something contaminated, it still feels like I did, and I can't shake it.
It's not just washing anymore — I also get stuck mentally replaying who touched what, checking over and over in my head whether I made contact with something "contaminated," even when I already know the answer. It follows me through the day and even into trying to fall asleep — lying still with nothing to distract me is actually one of the worst times, because the thought gets louder instead of fading.
I've tried delaying the washing, capping how many times I do it, naming the thought instead of obeying it, and reframing it as being about the person rather than actual dirt — and some of it helps in the moment, but the pattern keeps coming back, especially with specific people who really get under my skin. It's exhausting, and I want to go back to not thinking about this at all