BF, It could definitely be linked to your OCD and catastrophic thinking related to general anxiety disorder. I know that when these types of thoughts hit you they can be torturous. I'm so sorry that you have to struggle with them...

One thing that has really helped me manage those types of thoughts was not going on another med, but taking a small dose of seroquel in the morning. It is very good for OCD and anxiety, but it generally doesn't carry over from a nighttime dose to the daytime to treat that. It took me a little while to adjust to the sedation... now it just has a calming effect on me. It made a HUGE difference.