what do you think about altcoin,do you think is the time to buy? am afraid because all my money is heading to zero..

Alts were overestimated during the rush in December 2017 - there were so many promises made by various projects that could never come true.
Since then some projects even launched their main nets - but that brought zero help for their tokens, which are still at least 10 times below the ICO price.
This is not the end of crypto, but definitely some "natural selection" processes are going on that would sanitize the market.