If you don't already know it, I would call your piercer and double check what type of jewelry you have. There are some people that are allergic to surgical stainless steel and that could possible cause the itching and pain. I can't imagine it causing a smell. I am wondering if you need another course of treatment for the bv, maybe the first course didn't quite take care of the problem.
I will be honest as well and say that my daughter recently had this. She called me describing her symptoms and I told her to call her gyn. right away. She had a further complication when she had an allergic reaction to the medication and for 2 days she felt like her vagina was on fire. Of course, as soon as she felt pain like that she called the dr.
This was a bit ling winded, but 1 call your piercer, and 2 call your dr afterwards.
I hope that you get things sorted out soon!
Life is short; enjoy your pain.