Thanks for your question. My name is XXXXX XXXXX I'd like to help you out.
I'm terribly sorry to hear about what you're going through with these fears. If you have had obsessive thoughts in the past, then the problem more likely has to do with those obsessive thought rather than your tongue specifically. At this point your tongue just seems to have become the focal point of the obsessive thoughts, and it is not uncommon that throughout your life the obsessive thoughts would focus on different things
This type of problem is very commonly associated with obsessive compulsive disorder. Repetative thoughts of any type throughout your entire day can be very scary, frustrating, and exhausting. Fortunately this is a relatively common problem that people experience, and it is generally very treatable with the right combination of medication and counseling.
If you are not already in counseling I would certainly recommend it, which will help you greatly to cope with these thoughts. However, either way it seems that the medication that you're currently taking either isn't working, or isn't working sufficiently, so it is also important to have that reevaluated. There are a lot of different medications that can help you to get these obsessive thoughts under control, and many times it is just a matter of finding the right medication and dosage that you respond well to. I'd suspect that once you do find a more helpful medication, that you will have a much easier time controlling some of these obsessive thoughts on your own.
I definitely wish you the best with all of this and if there's anything else I can do to help just let me know.