Hmm...I don't know about the concussion being a factor, as I don't know how that would affect hormone levels, but I do believe Hamster gave some excellent advice that I hope you can follow.

I'll ask my mom about the concussion...she was a few credit hours away from being a certified nurse, and she's still incredibly knowledgeable in regards to medicine, at least on a fairly basic standpoint. She may be able to offer something.