I’m eight years in on Letrozole - I don’t have any of the most common symptoms, joint aches and pains and menopause type symptoms - flushes etc. Letrozole can thin bones so talk to your oncologist or GP about vitamin D or calcium supplements. It can also cause vaginal dryness - vaginal lubricants will help, as can oestrogen cream (sounds counter intuitive I know but the amounts are tiny). Main thing is that if you have significant side effects, don’t suffer in silence. Short breaks, changes in brand, small things can help. Best wishes.