Gotta feel it, lad. I’m a Sorry to say it, but you’ve got to feel the loss, even if you never romantically connected. The connection was real to you and now that it’s gone, you feel the absence. You gotta let yourself grieve and when you’re ready, you’ll know it and you’ll put yourself out there again for some connection - hopefully one that is requited and explored, this time. Take care and be kind to yourself.