I (26F) am finding it impossible to move on from my feelings for coworker (34M)

I’ve known my coworker for 6 years (closer for the last 2 years). My coworker told me when he became single last year and was looking for an opportunity to ask me out in person. I never went because I was shy and froze up and was scared of losing him as a friend. We never talked about it directly and he never directly asked me out. Just as I had worked up the confidence to open up that door and go out with him, and while I thought he was still single and I had an opportunity, I found out that he had a girlfriend. I was rather surprised. I now know they’ve been going out for a year at this point, which means I didn’t hear about her at all until 6 months into their relationship.

I have tried everything to move on. Working out, new hobbies, travel, journaling, letting myself feel my feelings, prayer, telling myself he has chosen his girlfriend and she makes him happy, logically considering obstacles to us being compatible….everything.

Recently I said “as long as you don’t hate me, we’re good” after a minor miscommunication and he said “no, it’s the opposite.” We’ve gone out in a group of friends and I am 99% sure the way he looks at me is more than friendly. The conversation in the group basically becomes banter between just the two of us. He compliments me regularly about personality/professional traits. He is not a touchy-feely person at all and he says it really hurts him to see me sad and I’m one of the only people who he really thinks about conversations with outside of work in terms of how what he said may have come across or how I was affected by it. Why would he not be sending complete platonic signals at this point? Or is this normal behavior that I am reading too much into?

I would never want to jeopardize our professional relationship or friendship or interfere with his relationship. I think I’d be better at moving on if I thought he never was interested in me and this was a one-way thing. I’ve been there before and got over it. It is getting to the point where every time I talk to him, I feel down afterward because I can’t spend more time with him and get to know him even better.

I am so close to asking him to just tell me that his girlfriend makes him incredibly happy and have him describe how amazing she is and explain how he is probably going to marry her so that I can hear his happiness and accept reality and move on. I realize this is probably not a smart idea but I currently see this as the only way my brain will register closure…by hearing from his mouth that he chooses her.

What do I do? I don’t want to leave my job and I don’t want to lose him as a friend. I know a lot of advice is to start dating someone else, but I am not the type of person that dates casually or frequently and don’t even think I could date right now if I tried because I would be thinking about him and comparing others to him which isn’t fair to other guys.

TL;DR: I have persistent feelings for my coworker who I’m 99% sure was going to ask me out last year. After I ignored his attempts to hang out in person because I was shy and frankly scared of losing him as a friend altogether, I thought I still had a chance once I came around in a few months. Instead, I learned he got a girlfriend who he has now been with a year. Nothing has happened between us but we are emotionally close, talk often, and the flirty vibes have not completely dried up. I need help moving on before I spill my guts to him.