Okay soo.... What is your advice, what do i do now? I changed my password.
Check the "bitcointalk" url twice before entering your login details to avoid being compromised again 
And since his sale has failed, he left me Negative Mark, even if i don't have any connection with him O.o . I guess nothing can't be done by that question? 
Mods can remove it, however, it is rarely done since trust isn't moderated. Neglect this cockroach, he has enough negative trust to be ~=inexistant. Since your account is safe now, you can lock the topic tho.