Regarding cortisone, my understanding from the collection of doctors sipping single malt scotch on my tab, is that it is best suited for normal folk that have an extraordinary event that causes inflamation. The cortisoine reduces inflamation which speeds the natural healing process. Assuming that this is the case, it should be of greater benifit than simply to block pain. The doctor that I chose to stick with, who eventually did my surgery, indicated that due to the chronic nature of my situation cortisone would be a waste. I had been sucessful many times in eliminating the inflamation, I just couldn't do anything without it returning. I was many years on this journey before I found that doctor so who knows what he would have suggested earlier in the process.
As far as orthotics go, I don't know what type you have tried but my leather and cork ones, meant to be transfered to multiple shoes, are very limited. They are free to slip away from the pressure toward the inside reducing the level of support they provide. My daughter has a great pair made just for her training shoes (seems like yesterday we were dealing with training pants) that replace the entire insole. That's the way to go! If you have different shoes but with a great degree of similarity you might get away with transfering the orthotics. Good luck with your new attempt to find competent care. I suppose I regret taking a decade off somewhere in the process. I shouldn't have let them wear me down. How many times can you handle being told that it should go away in three weeks!
Hang in there!!