Does a conditional divorce pronounced by an OCD sufferer due to obsessive thoughts and fear take effect, especially since he repeatedly uttered the conditional statement out of fear of it occurring?

Divorce does not occur with doubt. As long as you are not certain about conditioning the divorce on your wife's return, then no divorce will occur if she returns. The divorce of a person afflicted with obsessive thoughts (waswasah) who is overwhelmed by his condition is not effective, for he is like the imbecile, the insane, the delirious, and anyone whose intellect is overcome by illness.