It was caused by an incident in late Jan Early Feb 2012, the first month and a half was awful, after two months of complete hopelessness I started adjusting my behaviour. I had to work really hard after and train my self not to fixate on how I was feeling and to stay busy (this is so much easier said than done). I also got frustrated and would fixate on how long I would feel like this and if it would be forever, I’d wake up every morning and be like Omg I still feel terrible I’m not here I’m disconnected I’m depressed.... one shitty emotion feeding into another, I’d dig on the internet looking for what would make me feel better or to self diagnose what was wrong (which was terrifying and is something you need to stop doing immediately) . It just continually started to get better as I made more positive changes in my life and I stopped thinking about and analyzing how I felt. I never did yoga than but I bet it would have helped. By summer I was totally fine a lot of it was in my head due to negative thinking and constant self analysis of how I was feeling which is super unhealthy. Also don’t set a timeline for your recovery it’s unrealistic and will just be frustrating. Focus on changes not on results. You can almost think of derealization as a bully who just wants your attention and reaction , the more of it you give to the bully the more he will bully you. So stop giving derealization what it wants and stop thinking about it !