Getting Over a Crush

Hello all, this is my first time posting on a forum in years, but I’m so desperate right now I really need some support. I’ve had this serious crush on a guy for the past year. He’s really been the only crush I’ve had in my adult life, I’m a very picky person (I know, this is a fault I’m trying to work on) and I don’t often find guys I really like a whole lot. This particular guy seems to be, this is going to sound cliche but it’s the way I feel, everything I could dream of. Not only that, but I feel a deeper connection with him in ways I can and can’t explain. We share so many similarities I feel like. I’ve seen him almost every week this past year because I volunteer weekly at a place he works. We’ve talked and texted, mostly about the work-related matters, but about personal things too, especially right after I first met him. He was in a relationship when I first met him, so I kept my distance, but then he broke up I kind of went a little crazy chasing him. I asked him out on two dates, both which seemed to go so well, except he told me on the second one, in terms similar to, “I’m not ready for another relationship now.” I never told him straight out how I feel but I know that he knows because of how I’ve acted. He’s entered my thoughts in some way almost every day for this past year and I’m mentally exhausted. I’ve never been able to build up enough strength or think up enough reasons to let him go. He seems to have just grown on me and become better to me more and more as the time has gone by. I need help with letting him go, and I don’t really know how. Please, any advice?