(PJC104, I have some advice, but realize that I am just an ordinary guy who has been dealing with OD like so many others. You have to decide for yourself whether the advice can help you or not, since every person is in a unique situation. I am not a trained professional, merely someone who's dealt with OD with much success and now has a personal perspective on the subject.)
First of all I have to tell you that I understand the frustration. My obsessing was so bad that it caused me to become horribly nauseated. This lasted every single day for about one and a half years. Imagine how your stomach feels when hung over. Well that's how I felt day after day, from the moment that I woke up to the moment that I went to bed.
You have to read a book called Brain Lock, Free Youself From Obsessive-Compulsive Behavior, by Jeffrey M. Schwartz. I have a great doctor, but I wasn't getting the feedback that I needed from him. This book brought it all together. In conjunction with the meds, counseling and the behavioral therapy that the book discusses, I've come a long, long way. Soon enough you will also, I'm sure.
In the meantime, I'm afraid there are no quick solutions. Staying busy helped me a lot.
I do have one suggestion for dealing with it, though -- something that made a huge difference for me.
First, be mindful of your thoughts. Then, when the obsessing begins, calmly stop the thought, tell yourself something like "ok, this is the disease kicking in, not me", and refocus. Simply move on.
At first you're going to be doing this over and over, but it will eventually give you great results.
Why is the above helpful? To get the details, read the book I mentioned. In the meantime, this is my way of explaining it.
Well, first, in order to stop an unhealthy behavior, you first have to recognize that you're doing it. This seems obvious, but many times we indulge the obsession for a long time before we catch ourselves. The sooner we recognize what's happening, the better. This is why being mindful is so important.
Second, you want to undo the behavior without accidentally reinforcing it. When we tell ourselves to stop thinking about it, we're actually reinforcing it. So, by simply and calmly acknowledging it for what it is - the disease - and moving on, you're teaching yourself to refocus without making a big deal about it. In other words, no accidental reinforcement. You are not fighting or struggling with it. Leave the emotion out. It's simply an annoyance. And the less attention that you pay to it, the quicker that it will fade.
There was a time when my OD was so severe that I wasn't even able to do the above. My brain was a broken record playing the same tune over and over. However, once I got a little better it helped me a lot.
Good luck and hang in there. There are better days ahead. It just takes patience, therapy, meds, positive behavior, and time.