Actually if you check the charts, Bitcoins experiences quite big dip at the beginning of the year all the time. The was dip at the beginning of the year since ever. Hard to say why this happens, but the pattern keeps repeating. So, I wouldn't worry so much. It will stabilize again and we'll be back to ATH in summer. Just be patient and HODL 
Yes its true, its better to wait than to sell it at a low price. Many of them are panic selling without noticing that selling their coin in dip, will just cause a huge loss from the side of investors. Where if you'll just wait until it recover then the chances off you to have income is very huge than usual.