Am I wrong for distancing myself from this guy? (kinda long)

Background: I am a 23 yr old gay male. He's 34. We are both undergrad seniors with similar majors at the same college so we see each other frequently.

Story: About a year ago, he was an SI instructor for one of my classes so I got to see him often and we talked a decent amount of times. He would subtly flirt with me in regular and SI class, but it was the constant eye contact and staring he made that made me believe he liked me. Trust me when I say this. A friend of mine in that same class also noticed his strange behavior around me. So I took this as a chance to ask him to hang out outside of class. I did the best I could to ask and he gave me an enthusiastic "yes!". He also proposed that we go hiking together. So it seemed like he was really into this.

However I guess I was wrong. Long story short, we kept in touch through school email to plan it out. He gave a bunch of excuses: told me when he was free in person, but backtracked on that; he proposed another time but when I followed up on that, he made another excuse. So I put the ball in his court and told him to tell me when he was best available. No reply. Seemed to me that he flaked out on me. After this happened, in person he would look and talk to me as if it never happened. To me, the way he rejected me was pretty disrespectful and he thinks that we'll still be cool afterwards without any explanation? Um no... So I began to slowly distance myself from him.

A year later, we see each other constantly in the hallways. He STILL stares at me often but I don't entertain his flirting anymore. He's tried to talk to me before but I didn't keep the conversation up and he never tried again after that. Then he would smile and say hi when we pass each other by. But now we only give each other silent head nods. I don't go out of my way to make conversation, to smile at him, or to look at him. I only say hi when he says hi but that's it. I want to be indifferent towards him. Just pretend like he doesn't exist. Really trying not to be rude or angry as I do this but I can't be nice and friendly either. I had huge feelings for this guy but I don't want to get obsessive again. But I hate how he's trying to get my attention. For instance, he would try to say hi to my friends but completely ignore me instead when he's never done that before. He doesn't know my friends well enough to just do that out of nowhere. Also, 100% speculating about this, but I'm pretty sure there's a girl we both know from his SI class that he's been talking to about me. She was always nice to me but now she's been acting a little distant as well. They both have two classes together so I just know he gossiped about me.

So was I in the wrong to distance myself? I don't like having to cut people off like that but I felt it was needed here even though he's still in my head somewhat. I still do like him but not NEARLY as much as before. He is a nice guy but his fake/flaky actions really rubbed me the wrong way. I really just want to tell him why I've been acting the way I'm acting since he won't be coming up to me anymore it seems like. Instead, he'll just steal glances at me any chance he gets. He's just very annoying and confusing. What are your thoughts on this situation?