In etherscan i see that in my wallet are two types of fuck token (probably old and new contracts) , but in myetherwallet I have info that I have only one. Does this mean that the tokens on the old contract address are worthless?
Yes, the old contract tokens are worthless. We found a mining exploit and issued new tokens 1:1 for all holders. If you're worried about sending the wrong token with MEW you can "add custom token" with the following information:
Contract: fucktoken.eth
Decimals: 4
Symbol: FUCK