Is it permissible for someone suffering from obsessive-compulsive disorder concerning divorce to seek guidance, and how can they do so?

"Istrā‘" (seeking witnesses) is valid for one who is coerced into divorce, by having two witnesses attest that he is divorcing under duress. As for the one afflicted by waswasah (obsessive doubts/whispers), he has no need for "istrā‘". He must instead disregard these whispers and pay no attention to them. Any divorce pronouncement he makes due to the overwhelming nature of waswasah is not held against him.