I have OCD too, pure O. Though it doesn't bother me that much, actually people can live like this all their lives never thinking something's wrong with them. But when I get stressed and I don't sleep, my hypochondria and OCD kick in, and after that I get depressed. So it sucks big time.
OCD and hypochondria are closely related. Because if you get obsessed about an illness you will do irrational things to relieve you of the anxiety. I checked for about 2 days symptoms and everything... I actually thought I was bipolar. Then it passed, now it seems silly. But...during the obsession period...it felt so real.
Also I read the article about Si (thanks for the link) and it's pretty awesome.
My solution to that is doing sports (rent a bike, go to the gym, run, or just take long walks with someone). Whenever I get very introverted, very obsessive and everything I do that and I start feeling better. Also you need to sleep enough. Sleep deprivation sucks even more if you get obsessive.
My introverted moments are kinda cute, I get to see another perspective and it's interesting...I like them.