The bitcoin market has never taken money from me besides the occasional transaction fee and whatnot, so I can't even imagine what it would feel like buying a $2800 bitcoin and the price immediately going to $2000, but I'm sure that guy is in this thread somewhere.
I can remember buying coins pre-gox failure only to have them drop in value a large amount. It didn't feel great, but now I wish I could go back in time and buy more at the same time. At the end of the day, everyone who has ever held Bitcoin has made money. If you bought at $2700 and are sad about losing, 1. you shouldn't have invested in a crypto at the top of a parabolic rise and expected to see immediate returns if you can't afford to lose some. And, 2. just keep holding, no one who has held Bitcoin long term has ever lost money.