Broke up earlier this year.
Long back story short; an extremely good friend and I started hooking up and dating. We'd met at our last job and really hit it off. A lot of fucking around lead to finally dating, but when it all came down to it we had the realisation our attraction to each other was limited. It was always missing something, a special chemistry, and we dragged it out far longer than we probably should have. We reconciled that ultimately we probably decided to date out of a mutual loneliness; neither of us had been in relationships for a very long time, we were in a shitty job together when we met, quickly became extremely good friends, and that mutual loneliness spearheaded something that was probably never going to work.
She initiated the breakup but the writing was on the wall for awhile. I was gutted. Just felt like one big failure of regret, empathy, communication, and everything else. Did what most people do and overthought everything, whether it was doomed to fail, if I could have done better, if we could have fixed it, if it was a good idea in the first place, and the consequences of breaking up. It really hurt both of us because there was that lingering possibility it'd just be too hard to see each other again. Worsened by the fact that despite no longer working at our old job, we actually worked right next to each other at a new job. So it felt like everything was unravelling. Took two days to really sink in and hit me. Walked in the door after work and just broke down into an absolute mess. I don't think I've ever cried that hard in my life.
We worked it out though, within a week or two. A bit clumsy and awkward at first, but once the emotional draining was out of the way we were able to rationalise the circumstances that lead to us being together, the value we still had for each other, and reconciled the situation. Rarely happens but we've remained both colleagues and extremely good friends. We still hang out and talk outside of work very regularly, strictly platonically. We still have mutual friends that we spend time with, no hard feelings. It's all gravy, and back to how it really should have always been.