of course i don't know what it is and only a doctor could tell for sure (and maybe not even then) but i just saw you say that you don't have health insurance, so i'll offer another idea.

your symptoms also sound familiar to me. the stiffness sounds like when my muscles spasm and heat or ice help that (for me ice helps more, but others find heat to work better) and that sharp pain sounds like when something (for me, i'm assuming my ligaments that hold the SI together) is either loose or out of alignment or something. then its important for me to stop what i'm doing and maybe stretch a certain way until it feels a little better and then grab the ice. tonight in fact, i was doing something and felt that twinge and so i went and sat with an ice pack for awhile and then it felt better.

if you can get to a doctor, please do. if not, see if heat and/or ice help, so long as you're careful, they probably can't hurt too much.

just another idea,

feel better,


sue

Spondyloarthropathy, HLAB27 negative
Humira (still methylprednisone for flares, just not as often. Aleve if needed, rarely.)
LDN/zanaflex/flector patches over SI/ice
vits C, D. probiotics. hyaluronic acid. CoQ, Mg, Ca, K.
chiro
walk, bike
no dairy (casein sensitivity), limited eggs, limited yeast (bread)