I can only speak from experience here. I've been in love a few times and every time it ended against my wishes I felt as devastated and rejected as described in the OP. The first time it happened I was 17 and I got equally obsessed with trying to set the record straight...
Not long after I hit it off with someone else and did the whole thing again, but I wasn't quite so obsessive that time. I had already experienced the light at the end of that particular tunnel and realised that I could get back out there, take a few risks with my self esteem, experience a bit of rejection but ultimately gain the closeness I wanted with someone else.
Eventually, in my thirties, I met the woman I would later marry who is still, many years later, my dear and cherished wife.
The whole idea that there is a single compatible soul-mate for everyone is a statistical nonsense. Every individual is capable of finding a mutually beneficial bond with millions of others, not just one, but if you don't put yourself at risk of rejection you'll never find any of them. It's only once you have met that person who ticks all, or most of your boxes that they become your soul-mate by
mutual agreement and need. If they change over time, or you do, then that mutuality may be lost and you move on, but it doesn't mean you are lost, unlovable and destined to be lonely. You just have to get back on your horse and ride back into town.
However much you love this girl
@sad guy , it's clear it's no longer mutual. I never got the chance to get out my apologies, offer my explanations or set the record straight with any of my exes, however much I wanted to. I doubt you will either, but there are plenty of women you have not yet met, and if you can fall in love with one, you can do the same again.
Good luck to you and I hope you feel better about things soon. You seem like a decent guy