Oh Becca, you must be feeling rotten! No wonder you had so much pain. I am so glad you got checked out and the ER was thorough by doing the CT.
In case you are feeling bad that maybe CRPS did this to you, know that my 15 year old healthy son broke his metatarsal twisting and going down this year. So yes, your bones might be more brittle with CRPS or it might've happened anyway.
I'm with Bio on the Vit C. 500mg daily for 4-6 weeks is the orthopedic recommendation. If you don't take calcium or Vit D now might be a good time for those too. I think it is a good sign that the fracture didn't show up on x-ray, at least it is not too bad and not displaced. If it stays put you'll avoid surgery and hopefully heal relatively quickly. When my son broke his foot, they did serial x-rays to make sure it was staying in place as it healed and had healed adequately before weight-bearing. A follow up CT sounds reasonable, especially in light of CRPS and bone issues.
I hope you heal up soon,