Quotes are in decline for many coins now. This situation makes me a little nervous, what should I do now?
The price volatility is the nature of bitcoin, everyone will be happy with price rise and worried about the decline, don't be panic or nervous at such situations, if it goes low it will recover for sure, now little correction has occurred in bitcoin and is showing an upward momentum so I feel all worries will vanish soon.
Just close your eyes and relax to look at the market condition where it seems someone play it with huge amount of money.
They are trying to dump and makes a new investor to get panic and cut the loss which it is a benefit for them to gain some profit.
Hold your coin as a long term investment , spend it some and you will feel more than happy to see the future bitcoin price , just like when it moves from $900 to $15k.