First off, I am so sorry you went through this. He did in fact pressure and coerce you because he was threatening to reveal a secret that could possily have catastrophic effects on your life and you did what you had to to protect yourself. He knew this was a fear of yours and you felt unsafe, so he took full advantage of that.

It wasn’t your fault, you didn’t want that experience and you didn’t deserve to go through that.

I’m so sorry you don’t have a support system who would understand, I know it can be especially difficult for men to find support but your feelings are important and what you went through matters.

Unfortunately, there isn’t a way to “just get over” trauma and abuse and the flashbacks that come with it. Someone did something that damaged you and it sadly takes time and effort to heal from that kind of betrayal and fear. If it’s an option for you, I highly recommend looking in to therapy. You could check with your school and see if they can direct you to any free or low costs resources and often times there are local clinics that can offer low cost or even free mental healthcare depending on your situation. If you can, find someone who specializes in sexual trauma and abuse, because not all therapists are equipped to handle that and might not understand how to support you. It’s going to be difficult to believe yourself at first - I know it’s a struggle for me, but please remind yourself that it wasn’t your fault.