Cortisone Injections

At my follow-up appointment with my rheumatologist this afternoon, we discussed how the new biologic is working and what my options are.

Although I have seen some mild improvement (like spikes being a couple notches less intense, and in the level of pain in my shoulder blades), I was told that it should be helping my pain quite a bit more.
Here's the problem: I don't have many options.
I have had allergic reactions to Remicade, Humira, Enbrel, Simponi, Imuran, 6MP, Advil, Ibuprofen, Oxycodone, Celebrex, among others, so my choices are limited. Not to mention that I am almost positive that I am already beginning to react to this new medication. Last month, for instance, a few days after the injection I had a major throat swell. During that time I was also under SEVERE stress and I had a dental appointment, which is widely known to cause throat swelling in most HAE patients. It could be that the combination was too much.
With that said, my latest injection was on Monday, and I am currently pretty swollen all over my body and I feel as though one bad day could put me into another episode very quickly.

So, even if I don't develop (or have not yet developed) an allergy, it is apparently still not working at the level that it should, and we are essentially out of options at this point. There is one option: My rheumatologist has sent in a requisition to radiology to undergo an Ultrasound-Guided Cortisone Injection riiiiiiiight into both SI joints.

And I am being a baby about it.

I am terribly nervous. Just imagining the size that needle must be and how much that joint already hurts, just the simple thought of a needle going into a joint or a bone makes me quiver.
I know that other people do it all the time and have told me that it "isn't all that bad" and that the pain relief will make it worth it, but I would still much rather be sedated. Like a total and complete wuss.
I can be strong about a lot of things - I mean I give myself injections into my abdomen three times a week - but big scary needles freak me out.
I have no idea when the appointment will be, but I am sure I will tell you all about it after the fact.
Fingers crossed.
Wish me luck!!