I'm sorry to hear about what a rough time you're having! That's terrible! I was hoping you'd be feeling much better by now.
Are you having any fevers in addition to the high blood pressure when you have these attacks? I'm just wondering because I have a friend who was really sick for months and had pain similar to yours - upper right instead of lower right - it ended up being her appendix was leaking. Because she had other health issues (overweight), she was just chronically sick, rather than the acute symptoms of appendicitis, and doctors overlooked this possiblity until they were doing exploratory surgery. I'm not saying that's what you have, but could it be that Crohn's is affecting your appendix? Plus, you're on steroids, which can affect the presence of those symptoms used to diagnose another problem.