I have been having similar problems to yours... sad
DD is 10 months now, and I have had bad cramps/back ache that sometimes makes me nauseas (sp?) on and off for a while now. I am still breasfeeding dd, although she only has about 3 or 4 feeds a day now, but my period still hasn't returned.
I first noticed it when dd was a few months old, I went to the physio as thought it might have been my back causing the problems. She said it is probably hormonal and also said my back was bad so that wouldn't have been helping matters. She showed me some excercises to strengthen my back which I did for a while, and from memory I don't think i had these cramps for a while after that.
I still get these awful cramps every now and then. I'm trying to pinpoint what sets it off (food, activity, time of the month etc...and dd was delivered via c section so sometimes i wonder whether that has anything to do with it)...but strangely i have noticed that it seems to come to a head after a couple of glasses of white wine?...when they come, i drink a couple of glasses of water and just chill for a bit, and they seem to subside.
Sorry I can't give you any advise, but just thought I'd share my story, and i'll be keeping an eye on this thread to hear other opinions etc...
I hope your feeling better soon smile