It was actually that he didn’t get what he wanted out of me. I just want to make sure I know what I’m talking about when I have to go to HR
In the original situation you were both at fault.
Depending on the situation, for instance if he was your direct supervisor you both could be fired.
If he wasn't he could transferred and you fired
Sadly that seems to be ASANTS and how they read the HR regulations.
In the current situation it is sexual harassment, you have broken off the relationship and he is harassing you.
That is illegal.
Going to HR is the right thing to do.
Make sure you have everything written down.
Who, what, where, when, times, dates, and if you can witnesses.
Make it clear you feel unsafe and harassed.
The previous relationship is off the table at this point.
His current actions are now the only issue.
They will have to take action.