My younger cousin had gall bladder stones 6 months ago and got her gall bladder removed. When she had them, she was in constant pain, especially when she ate, her appetite quickly dwindled, lost a lot of weight (I think around 40-50 pounds, not 70) and had frequent nausea. Alternatively, peptic ulcers present with very similar symptoms. Having pain radiate around parts of your body is a known phenomenon called referred pain. For example, pain at the right tip of your shoulder blade can actually be due to your liver or gall bladder functioning.

Even if it isn't gall bladder stones, it's gastrointestinal and the best way would be to get a scan to see what's going on. Infections can cause this as well, although they don't tend to last that long, unless your immune system was already weakened or you caught something rather nasty, which is unlikely given no fever.