Doctor says my broken ribs are metastatic cancer - what?

Hey there - I really appreciate any advice that anyone can give; I'm really confused and pretty scared.  I don't think this is the right forum for this, but I don't know what one IS right, so please bear with me.

About a month ago, I was shoveling snow, came inside, and by nightfall I was in a lot of pain, right side, ribs.  I figured I'd pulled my intercostals, as I'd done that a few years ago and the pain was the same.  I toughed it out, went to a few physio apppointments, but then about two weeks after that I was lifting something and felt and heard a distinct pop in my rib cage, felt like it was right in front where the rib meets the cartilage.  The pain was so intense I went for an x-ray.  The x-ray was inconclusive so they sent me for a CT scan the next day.  While the tech was injecting the contrast into the IV, the union blew up and no contrast went in, so not an ideal CT scan.  The CT revealed a suspicious-looking fracture of my right 6th rib, on my side, not in front.  I am a healthy 51-year-old with good bone density, so the internal medicine doctor on duty ordered a mammogram, ultrasound of thyroid, and blood tests.  Additionally, within the past year I've also had a brain MRI (I have unilateral tinnitus and they were screening out an acoustic neuroma), a routine pap (abnormal, further testing six months), and a routine colonoscopy (clear).  So far, all the tests except the pap have come back clear (for the dudes - abnormal paps aren't that uncommon and often resolve by the next visit), and my blood work is all within normal ranges.  The doctor then ordered a full body bone scan.  He called me a couple of days ago with the result of the scan and told me, over the phone, that there were lesions that lit up on both sides of my rib cage, so to him it didn't look like myeloma - he said if he had to be blunt, it looked like metastatic cancer.  Now I'm waiting for a CT scan with contast of my abdomen to try to find the primary cancer.

Apart from feeling EXTREME anxiety about this, mostly I feel great.  The pain from the right side rib fracture is bearable, but I also feel pain in my back where the rib meets the spine, and in front, under my breast.  Not a lot, maybe a 2, but it's there.  I feel no pain on the left side.  I realize that people with cancer can feel great - until they don't.  I'm still having a lot of problems believing that this is a cancer that's metastasized.  I DO think there's something wrong with my thyroid (I have a small nodule, my mom had thyroid cancer, I have a lot of classic hyperthyroid symptoms but my TSH is normal, for what that's worth) but the doctor says it's very unlikely that this small nodule has metastasized.

I will have the CT with contrast next week, and of course if it shows a primary cancer, then I guess my questions have been answered.  But if it doesn't, what then?  Does anybody out there have primary bone cancer that started like this, or sounds like this?  Does anybody have any ideas for questions I can ask my doctor?  Please feel free to direct me to a better forum, if you think I might find more answers there.

Thanks tons - RRC