I just lost my unique BCH. I used Electrum, after the fork i sended my BTC to Bittrex, i download the Electrom Cash, used my private keys and saw my BCH, everything is ok, until after a little time Electrom Cash send my BCH to the same BTC Bittrex address.
So is a lost right?

Yes unfortunately your BCH is lost since you've sent it to a BTC deposit address.
Bittrex is the only one who can fix this for you but usually they tell you to double check addresses because they don't credit incorrect withdraws/deposits.