PTSD help

I’m not diagnosed I don’t even know if this is the right way to label how I feel. In September of my sophomore year in high school I was sexually assaulted. I was 16 at the time and to this day (I’m now almost 21) I still get a small flashback or memory from that night and no one besides my current boyfriend knows. My BF is understanding but he doesn’t know the whole story either, he comes from a very traditional home and he doesn’t really know how to deal with trauma or emotions. One thing though that really triggers the flashes is this band. This probably sounds really silly but every single time I hear ANY song from this one specific band I get really tense and I feel like I’m going to throw up. The boy who did this to me used to listen to this band constantly.

What can I do to help get me through my random flashes or memories of this, I don’t want to just shove it down because I know that will make it all worse. I just really need some help getting over it. It’s been almost 5 years.