I (19f) had a “relationship” with (16m) and I don’t know how to cope with it

Let me explain that I DO NOT believe the age gap is appropriate and would even go as far as to call it grooming if pursued.

Here’s the story:

I’m a highschool senior who JUST turned 19 due to an early birthday- and the fact that I was held back one year in elementary school due to chronic illness. I was in several classes (and still am till graduation) with this individual. We became friends several months ago when I was 18. I did not know his age- only of his grade which is a junior. My brother is a junior and he’s less than 2 years younger than me. It didn’t strike me as that weird due to these facts- although I should have been more aware.

We flirted- held hands- and I kissed him on the cheek and vise versa. I need to note that NOTHING sexual happened. He wanted to go into sexual territory with me- but I refused and drew boundaries. There was no sexual conversation or relationship in the slightest. It was fairly casual flirting and not a lot of people even knew of it due to the fact it was few and far between.

BUT the he asked me out in the hallway in front of his friends and someone who was also his girlfriend. He was in an “open relationship” which didn’t bother me because we were only casually flirting in class. I remember when he asked me in front of them.. and I said yes because it was sorta a “spur of the moment” thing.

Anyways.. you could imagine how I freaked out when it was revealed to me that his girlfriend was a freshman. I was utterly disgusted and felt horrible. I immediately brought up the ages with him- as well as the fact I would be turning 19 in like a week! So that also made me very apprehensive.

Then I asked his age just to check in case he wasn’t as I assumed he was- and no he was 16 turning 17 in MONTHS from then. At this time I was 18 turning 19 in a week.

Obviously i became extremely uncomfortable- never flirted again, although I sat in denial for 2 days.. trying to figure out how to best handle the situation. I phone called him and drew my line. We were still friends- but then him and his freshmen girlfriend started following me around. He kept trying to flirt with me which I didn’t like. I told them to leave me alone and go elsewhere but they didn’t do so.

Drew a hard line again and this kid is still trying to flirt with me- which is never reciprocated. Recently his girlfriend found my instagram account and several people on the bus are aware of my age. Nothing has come of it yet- so I have no idea if everyone will see me as a predator or what.. but the idea deeply bothers me.

Just because I broke up with this guy doesn’t mean I didn’t cross the line, nor does it mean everything is okay now. I feel incredibly guilty and disgusted. I was going to have a senior graduation party- but this whole thing has gotten me pretty self conscious about my age- and made me view all of my interactions with any highschooler (even my long time friends I’ve known for years) as inappropriate (which idk it might be 🤷‍♀️)

Am I an asshoole?