I am so sorry you have so much pain right now. If I were in your shoes I would get updated images. You can request that your primary care doctor order this for you and have it sent to the rheumatologist and your soon to be new pain management doctor. It will help to have everything ready and waiting for your fist appointment.
How long have you been waiting for your referral to the pain management doctor? I think you can request that your primary care doctor make that referral as well. It sounds to me like you are getting the run around? If that is the case then perhaps you can give polite reminders to your rheumatologist every few days? I do not mean to worry you but inflammation in your lower spine, if left un treated, can rub bone / pinch major nerve clusters and cause significant damage over time. It is very important that it is addressed as soon as possible.
I hope you can get them to pick up the pace and get things done. I would be terribly frustrated if I were in your shoes. Hang in there and know you are in our prayers.
*warm hugg* dani