Give your doctor a call and ask if they could prescribe you some pain killing ear drops - they quite often give them to kids when they have ear infections and since they are drops instilled in the ear and not taken orally, it could be they would be safe with your high potassium levels.
definitely don't take ANYTHING wihtout first checking with your doctor.
I hope you feel better soon - I had a horrible ear infection this past winter, so I can empathize with you about the pain it can cause :(
I would recommend you tell your physician about the intense pain and see what he/she suggests especially since your potassium is elevated.