Hi, I've had thyroid problems for the past 5 years, since I was 16, first it was overactive then it went underactive, it's been switching between the two ever since. I've had radioactive iodine twice, each time my thyroid level was normal for a short while, then it went overactive again.
Right now my thyroid level is apparently normal, and I've been taken off medication, (which was 100mg Levothyroxine) this has happened a few times in the past, but I'm already getting the symptoms of being overactive again.
Anyways, your symptoms are exactly what I had whenever I was underactive, the first time I had it I went from a size 10/12 to a size 16 in a year, I couldn't walk anywhere without getting bad pain in my calves and shins, even just walking for about two minutes was so painful! I ended up spending too much time at home. I felt cold all the time but I would sweat a lot, and I ached constantly, I also had hair loss, everytime I washed my hair, loads of hair would fall out, I didn't have visible bald patches or anything, but it freaked me out, it's fine now though.
I hope the medication works for you, and you won't be in pain for too long.
Goodluck.