You should buy now if you have money for it. Not to sell anyway.
You are not losing until you are selling your tokens.  Now your "loss" is only in your portfolio not in real wallet.
It's normal situation because this is market not bank deposit.  The biggest mistake is to sell tokens. Now is the falling phase, in April-June can be growth. Like it was in December-January.  It's impotant to keep calm currently and wait.


https://bitcointalk.org/index.php?topic=2721724