The FA yesterday cleared the FIFA ref, 37, of racially abusing Blues midfield star John Obi Mikel.
Clattenburg told The Sun: "To know you were innocent but that there was the opportunity for it to wreck your career was truly frightening.
"Racism has no place in football and this experience should not discourage those to speak out if they genuinely believe they are a victim of abuse.
"The messages of encouragement from those inside and outside the game helped me through the most stressful time of my professional life."
Mikel has been charged by the FA for an incident at the match officials' room after the game, which Chelsea lost 3-2.
Alan Leighton, head of referees' union Prospect, said: "Mark is very upset his reputation has been dragged through the mud by this process. There was no need for Chelsea to make the public aware of the allegation.
"There is also an issue of flimsiness about the evidence provided.
"What we now need is for Chelsea to accept the verdict, to fully apologise unreservedly to Mark for the actions they've taken in damaging his career and to compensate him for that."