Of course your OCD is playing tricks on you. What you have to do is fall back on past positive experiences. You know these thoughts are not real and you got better with medication. It could be that you just need a medication adjustment. There is always going to be some breakthrough thoughts and so you should really learn cognitive behavioral therapy from a psychologist as well. Controlled breathing, replacing negative thoughts with positive ones. In this case you would say something to yourself like "WHATEVER, I know this isn't real and I'm not going there again...NOW MOVE ON." It is kind of like yelling at yourself in your head. If you start to go there again, repeat the phrase. Don't wait because that OCD depression stinks. Been there, done that. But what I have learned is if I do have a "crisis" (this is what I call it when I just can't pull myself out of it), I go and up my medication. The last time I had this happen was in 2011...no problems since. But what I know and will always remember is that if I can get better once, I will always be able to get better. It may be some work on my part, but it will all be okay in the end.