I was desperate for my best friend's attention. When I have a lot of casual friends, but maybe 2 or 3 people (at best, and what subjects, and it depends on the day as to when I CAN) that I can actually talk to about thoughts and problems and things that actually matter and one of those people shut you out abruptly, it will cause definitely CAUSE some emotional over sensitivity.

And I only mentioned the bit about when we first met at the beginning to try to convey that I am quite okay being friend with this girl without wanting or expecting more.

I've completely white-knighted when I was younger, and it was indeed horribly toxic, and eventually I realized that and cut people out of my life. The 'the guy who did this and that' was me trying to convey that I feel like I'm the only person in her life that really tries to help her out without wanting anything in exchange but friendship and I felt unappreciated as though that friendship was suddenly yanked away with no explanation. Men generally lack an emotional support system, and when the only one you have becomes the reason you need one, it is stressful, thus the reason I posted here.