Casually Dated Students and Now Feel Guilty?

I’m a high school teacher, been doing this for five years now. I’ve always kept my personal life separate from the classroom to avoid any conflicts or misunderstandings with students or parents. But about three months ago, after a long day of grading papers and dealing with student issues, I found myself hanging out more often with an old college friend who’s also in education but works at a university. We started dating casually; it was nice having someone to share stories with outside the school environment. Then, last week, something happened that feels like a terrible mistake. We were just talking about my job over drinks when she mentioned how much pressure there is between teachers and students. I admitted that I’d dated a student once before I got into teaching, just for a few weeks, but it ended badly because of the school politics around us. It was only after this confession did we start texting each other more frequently. One night, she messaged me about feeling lonely and suggested meeting up at my apartment. We had been drinking quite a bit that evening; before I knew it, things progressed further than planned. She’s older now, she turned 26 recently, and in a serious relationship herself. But somehow, the conversation veered towards her old high school days and how she used to have a crush on an English teacher. That night, while we were getting intimate, there was this moment when I just couldn’t stop thinking about my students from last year. One of them had been particularly curious and flirtatious, always asking me for extra help after class in the empty hallway. We both knew it was inappropriate, but it happened a few times before I firmly shut things down. When we got back to reality, she left quickly without saying much; I didn’t know how to talk about what had happened. Now, even though my date last week wasn’t technically with a current student and everything felt consensual at the time, this whole situation has me questioning whether it’s ever okay for an older woman to play into those kinds of roleplay fantasies with someone in a position of authority? I feel awful about what I did. Is it just because we were both drunk? Or is there something more deeply wrong here that I need to address and change moving forward? Any advice on how to handle this mess?