Is there a chance to return all of the lost money invested when the chart goes back up? Let say, for example, I invested $3 to buy 21 TRX (Tron Tokens), usually a token under Ethereum platform but still working the same as other altcoins when the value goes high, where the price is around approximately $0.14 per TRX. A week later, the token price is raised to $0.21. the following days later it dropped back to $0.14 and later $0.13 which is below the total amount of money I've invested.

Here's the worst case scenario: the price of TRX dropped to $0.001 after several days and definitely all of my investments are gone (30 TRX is equivalent of $0 instead of higher than $3 in return). Take note that this token/altcoin is legit and while taking better changes to improve while the investors are still counting on it. Now, the price of 1 TRX is now suddenly jumped to $1 after another few days.

The question is this: is my $3 invested after couple of weeks will be dropped to $0 and still $0 even after when the price of token drops to $0.001 and raised it back to $1 or not?
The value of TRX relative to the dollar fluctuates, as do all cryptocurrencies.  Whatever the price of TRX relative to the dollar when you sell TRX is the dollar amount you receive no matter what happens to the price between when you acquired TRX and when you sell it.