Chronic bladder or lower abdomen pain

I have been dealing with lower abdomen pain for 3 years. I have had many tests but really no results. testing has showed my bladder is healthy but I have such a throbbing pain it does seem to get worse when my bladder is full. Not knowing is so hard and having pain you can't control is aweful. I have had many tests done but no results, anyone out there have dealt with this type of condition please let me know I'm looking for treatment ideas or medication ideas