He left without saying goodbye... What now?

So I met this guy at work. He started working there a couple months I started, I'm 19 he's 23. When I first met/saw him I wasn't automatically infatuated, but I did consider him as good looking. We started to get to know each other more through work and I gave him a couple rides home, I eventually began to like him. Every time we would make eye contact it was like I couldn't breathe, I was always looking forward to work when I knew he'd be working with me. Considering we were co workers I never really made it obvious I was into him at work. We did flirt and talk but there were times where I couldn't talk to him because I didn't want to say something stupid. I remember for the longest time I thought I was wishful thinking and thought this was all in my head, the idea that he felt the same way for me. I mean, all the signs were there he just never made a move. I did however catch him stealing some looks and he was super generous and sweet with me. But little subliminal things would make me second guess his liking towards me. Like: he has my number but never texted me (he did say he wasn't a phone person though but still) I also initiated to go on a hike sometime since we both like hikes. So yeah that's the gist of how I fell for him, although I left out a lot more details, just this last week I show up to work and his name wasn't on the schedule anymore. My boss then tells me that he quit the morning before and said "I want to live my dream...btw not coming in to open today." I was crushed, like legitimately crushed, I last saw him on Friday when I went to get my paycheck and he quit on Monday morning. I was overwhelmed with emotions, because not only has he quit, but when I last had contact with him, I had no phone and he has my number. Now that I have one I can't let him know I got a phone since I never got HIS number. He walked out of my life and now work isn't the same anymore. Three days ago, his roommates came in asked if I knew Chris (not his real name) and I said oh yeah he used to work here, they said "he says hi", I automatically thought why he couldn't just tell me himself or why the heck I didn't tell them to say to him for me, I kinda just froze for a bit I miss him so much and regret never telling him how I felt for him. I don't know if I should linger on and hope he one day shows up in my life or if I should just give up and live my life. It's just crazy to think that the one guy I ever felt this way for just vanishes without even saying goodby to me himself.