I had almost the same diagnosis as yours, only left breast,in May of 2015. I switched to Letrozole because of the aches/pain side effects. I also experienced the hair loss and thinning. I no longer have the aches with the different medication, but I still had the hair issue. Now, though, it seems to be leveling off. I don't have as much hair in my brush and my hairline seems to be staying as is. I'm hoping this is the way it will continue; I was told it's very rare for someone to lose all their hair on these meds....so I'm hopeful!