sadly, I have
It happened a few years ago, and I just couldn't really cope with it when it happened on any level, I literally felt like I'd lost my mind for the five-six months that followed afterwards, was attempting suicide on an almost weekly basis before I was hospitalised and eventually doped up on many different kinds of medication to try and numb the pain (only name I remember was 'sertraline' off the top of my head, but there were about 4 different ones). I also started reading a lot of self-help books, and going to the gym, and it helped me regain control of my mind somewhat.
Slowly I recovered, realising that I wasn't in love with who she was when we broke up, I was in love with who she was when we got together, and that this person had gone, and that was my motivation to try and look past everything. I think everyone attempting to recover from a bad breakup needs some serious willpower to shut someone like that out of their mind for a long time, and I have serious respect for anyone who's done it successfully, and equal respect for anyone who's trying because it isn't easy!
I don't regret what happened though, since it showed me that I could feel emotions I never knew existed, emotions so beautiful that I know one day I'll want to experience them again, with the right person. However, the breakup also taught me that if I want to be happy, I can't let my emotional wellbeing rest on anybody else other than myself, and that loving yourself is as important as loving your partner. Being shy and unconfident I still struggle with the second thing though!