Yes, Effexor IS used to treat OCD. If you GOOGLE 'effexor ocd' you'll find a lot of info out there. I stick with it at the moment despite the fact it gives me headaches, solely because it seems to be one of the few that is effective and doesnt make me hungry. The worst one ever was mirtazipine , which leaves you hungry right after a large meal........nightmare .
I must have tried 10-15 different ones before I found one that suited me . But that was over many years.
I hope you find the right treatment for you, but I know it's especially hard when you have more than one condition, because a drug that helps one thing might make another condition worse. The trial and error process can be a long one, but it's always worth trying.