why the price dump so much?

Bitcoin has fallen in value recently and most alts tend to follow bitcoin and fall in price at the same time. If bitcoin starts to rise in price then COMM will probably follow. When COMM launched bitcoin had just recovered from a big crash and everyone was optimistic and buying. Now bitcoin is crashing everyone is selling, but it won't last forever.
Bitcoin actually rise a little bit in the past 48 hours.
COMM falls because there are much more competitors coming out these days.
Of course, if devs continue to deliver new features, COMM can still have a future.