Like Chartreux, I encourage you to try ice.
I had SI problems for years after a car accident, had injections, tons of PT for it, etc.. Eventually, the SI healed with minimal problems now. But I found ICE to do a lot for me. It used to feel like a burning spear in my SI, pretty much constantly. Lying down with ice was the only thing that helped (in terms of home-care).
I also got a lot of relief from an injection, done floroscopically and bit by bit, PT that helped straighten the joint out. I know many have also used prolotherapy for SI problems. It is supposed to add more connective tissue, to help stabilize the joint.
C4-T4 Scoliosis (disk degeneration, stenosis, narrowed neuroforamen, bone spurs), RT hip and SI joint damage from car accident. Also, pectus excavatum, supraventricular tacycardia and mitral valve prolapse syndrome.
Current meds: Ultram ER 300mg daily, breakthrough - hydrocodone 10-15mg, or oxycodone 5-7.5mg. .25-.5mg ativan as needed for sleep, Verapamil 240mg SR (for tachycardia). [/gray