Lynn-
It doesn't surprise me that having an autoimmune disease that requires constant attention to who you're around creates an anxiety response in your mind. Lets not confuse OCD with just being careful. If you have a disease that requires you to be very clean, stay away from sick people, and so forth, simply washing your hands and being attentive to who you're around doesn't mean you have OCD.
I think that the anxiety that you're experiencing is going to be normal for the amount of time you have to put into making sure you take care of your physical health. Thinking about a disease or illness can cause quite a bit of anxiety for anyone, whether it's cancer or something else, so anxiety almost comes along with the territory. OCD is about control. If I wash my hands enough times, I'll be better. If I go here, or avoid this situation, things will be better. The fact is that bad things are going to happen to us all regardless of what we do, where we go, what things in our enviornment we manipulate, it doesn't matter.
My recommendation would be to seek some counseling and see if a Psychologist can help you deal with these anxious thoughts you're having. A light dose of an anti-depressant such as Zoloft or Paxil will help also. But medications are not a cure all and should always be used in conjunction with good therapy...