Levaquin and vocal chords

I had a chronic cough which got worse and developped into bronchitis. My doctor gave me 10 days of 500 mg levaquin. Ten days later I went back, still coughing, even though the bronchitis was a bit better. He gave me another prescription for 7 days of levaquin with a refill.
A week or so into this routine, my legs started to hurt a lot. I thought I was just out of shape and needed to get back to the gym and do some stretching exercises. I could barely climb the stairs to the gym, but I must say that after working with the trainer and stretching a lot (and it hurt a lot) I was able to walk easier and the pain lifted quite a bit. . . for a while.
I also have developped total diarrhea, which made sense to me; because I was trying to kill bad bacteria in my system which I thought was causing the bronchitis.
Fortunately, last week I decided to go to another doctor because I wasn't getting better and I felt my old doctor was just overwhelmed by the health care system and was just going through the motions. This doctor, an ENT doctor, immediately diagnosed me with LPRD (acid reflux which goes all the way to the vocal chords, resulting in cough, tightness in the throat, etc.) I know he's right because I have felt the acid reflux thing at night when I have eaten late and had a couple of glasses of wine with dinner.
Tomorrow I'm heading to a gastro doc to attack the diarrhea, but I wondered if the leg pain had anything to do with the levaquin, since it came about after a week or so on the stuff. and lo and behold found all these postings which have now scared whatever shit I have left out of me!
I'm off to get some magnesium, as someone suggested and would appreciate any other tips anyone might have. My only tip is that stretching out your legs and butt muscles, does temporarily help a bit.