Okay, you guys are nice, but you are not explaining things well.
The OP seems to think that the Pirates are a normal part of gameplay. The rest of you seem to just assume he should know this and don't bother to explain it directly and clearly.
The Pirates are NOT a normal part of the game. As a matter of fact, I have never encountered them. They are a part of Mega Event, which is an optional part of the game that you select when you start a new game. The game even warns you somewhere that Mega Events can drastically alter the ballance of the game in unexpected ways. You have just learned what that means.
Mega events are all like this, they are powerful, unexpected, and introduce a drastic challenge. For a beginner player who hasn't played a lot of similar kind of game, they should be turned off.
Even so, it is possible to deal with every Mega Event, you just have to alter your strategies and way of thinking about the game.
As for the loss of the trade income, considering that all of your ships are going up in smoke, you should be saving a bundle on ship maintenance. Besides, you shouldn't need your ships for a while--all the other players are in the same boat as you. Instead, figure out ways to exploit the situation.