Good advise to take a deep breath and not panic sell. I personally prefer to buy and hold crypto although that strategy cost me a few years back with the fall of CRYPTSY.
Poloniex seems to be having a few issues dealing with the massive increase in trade volume over the last few months. From their site lagging to their recent decision to remove the troll box and ask moderators to help with support tickets. I currently have 2 outstanding missing deposit tickets that are PENDING. Hope they sort things out soon, i am a fan.