I've had this word in my mind that i can't get rid of it and i think everything i do that something will happen or affect other thing, but it's only in my head. i have ocd. how can i get rid of this problem? should i repeat word? do any action?

Self-help?: OCD can be challenging even for experts, but you'd be wise to try to find a good one to help. Prozac (fluoxetine) is not likely to do it by itself. Your ideas are worth a try. You might repeat it until it begins to be gibberish and loses the impact of meaning. A safe activity might distract you from it too. A CBT psychologist might have more ideas too. Good luck - I hope it works and you find a good therapist.