Keep trying for the Remicade. It will help you where most others may only do 1/2 the job. i.e. Flagyl will help keep your abscess under control, but it won't do anything for the fistula. Did your GI write to your insurance company? I've tried numerous meds for the same symptoms nd remicade is the only one that helped me. I felt great for the 1.5 years I was on it, then I developed remicade induced lupus and had to discontinue it. I am currently on Humira, it is ok, but not as effective as remicade for me anyway.
I wish you all the best, and I hope you aren't in to much pain.