I have only been on Letrozole and Prolia 9 Plus weeks - side effects were worst in the earlier weeks but wasn’t exercising thru joint pain initially- also get hot flushes . Could be interaction between them all - I don’t take daily oral chemo. From what I have read on here you may be getting a double whammy of bone thinning as both chemo and aromatase inhibitors like Letrozole thin bones.Could be the Prolia - as I said read worrying stuff on Dr Google about Prolia before starting it - time to get it checked out with a doctor. Please to hear it won’t defeat you -might settle down too like mine did - Just thought I’d let you know they are saying Prolia reduces bc recurrence significantly 18% I think I read.I also take Letrozole in the morning and that was when the side effects mainly occurred. Best wishes and hoping things ease for you.