Coping with having been “led” on by a partnered guy

Just a rant post. I’m feeling so bad right now and I just need to let it out. 30F.
So basically I’ve given up on finding someone through the apps, I’ve been app-free for 2 years now. I have hobbies (which consist mostly of women however), working on my education and part time work, so I have stuff going on in my life.

I was getting my country’s equivalent of a GED, there was a teacher who started giving me intense eye contact, and I stupidly fell for it because 1) I rarely get attention, not going to lie, it felt nice to be seen. 2) i thought he was interested, which, (in a perfect world) would mean he’s single. Or so I thought. And i was happy this was someone i came across out there, doing my life instead of apps.

Long story short, I enrolled in his class, there were subtle hints that indicated interest and some talking, so, after my final exam I sent him a message asking if he would like to meet up now that I was no longer a student there, I figured I’d never see him again otherwise so no harm done if it’s a no. Plus I’d avoid the “what if” thoughts had I not done anything. His reply was that he would like to see me, if he were single “at the moment” (his words), adding that I was hot (?!?). He said he would save my number, saying how he could be in a different situation one day, leaving his number at the end. Which I did not take, because why tf would I need it if he’s not available…

I don’t know what’s up with me but I after some digging (I know, not good) I found out who his girlfriend is and turns out they had a BABY last year. And they’ve been together since at least 2015.
I’m sad. All this time I thought he was single. The way he had talked about himself sounded like it was just him. I would have been okay with his reply if it weren’t ambiguous trying to leave the door half open..

I know this is nothing new for us women. Just the first time it’s happened to me.
Basically nothing really happened between us so not sure if I can say I was led on, but I still feel super upset and fucking angry. Maybe my anger is blown out of proportion. But I feel kind of lied to..Would it really have killed him to just say he was flattered by my message but that he is unavailable, and leave it at that. For fucks sake. His situation seems to be far from changing any time soon.

Any tips to move on from this? Words of strength?Despite knowing he is an asshole, I still feel sad about losing the “potential” of what could have been, no matter how many times I tell myself I wouldn’t want to be with a man who does shady shit like that. And it makes me feel like a fool, and once again invisible.