Patrick, I assume you read the post article here about obsessing about obsessing, so I will not repeat what was there. This form of OCD is a difficult one to help a sufferer understand what to do and I apologize if this doesn’t seem clear. In your post you ask if you should ruminate and I would re-word that to say exposure, since ruminating suggests ritualizing to me. You mention that you have a number of feared consequences (e.g. becoming poor) that you say may happen. This would not be enough. How would you attempt to cope with them in a positive way. How would you get on welfare and make the best of it. So part of the exposure would be very detailed that if these things happened what would I do. The reason for this is that if these things actually happened, life would go on and a person would have to continue. Though being poor would be very difficult, people in dire straits can still have enjoyment, even if it is less in their life.
Second, whenever you are doing something, we would like some attention paid to whatever good is actually going on. While learning to overcome this form OCD, it is important to learn how to notice whatever level of enjoyment is present, whether it be 80%, 50% or just 10%. It is learning to accept that this is my current best and so I might as well get something out of it.
The goal is learning to be able to have the thoughts in your head and feel anxious and learning how to cope with this while it is happening. This is very easy for me to say and it is lots of work to learn how to do. Obviously if it were easy enough to explain it all in a post, you would have figured it out on your own. But you can learn how to do this. Finally, it is true that OCD is both learned and biological. I have given you some advice for the learned part and an OCD specialist would be useful for you to be seeing. Medication would quite likely be a very helpful addition to your treatment and it is usually in the form of an SSRI for those who suffer from OCD. I hope this provides you with some help and hope.