Review about Letrozole

In 2013 I was diagnosed with hormone-sensitive breast cancer and was later prescribed Tamoxifen. I thought it was great apart from cramps in my calves during the night. Unfortunately in early 2015 I had another hormone-sensitive tumour, despite the tamoxifen. So after my operation I switched to letrozole. Now I'm suffering with stiff muscles, particularly when I'm resting, and really bad joints pain in my neck, shoulders, wrists and fingers. I take painkillers almost daily: paracetamol and/or ibuprofen. My libido is no longer what it was.