Sorry to hear this @OTISMYCAT .... How long have you been on the Letrozole?
Sadly, many of us do get aches & pains from the hormone suppressing tablets, but with gentle exercise & over the counter meds, it can be reduced ... I'd suggest chatting with your Medical Oncologist about it (and/or your breast care nurse, if you have one.)
Your Onc may also suggest changing you to Anastrozole or Exemestane (after 3-4 weeks off Letrozole), to see if they have less side effects. I started on Letrozole, then tried Exemestane & finally went to Anastrazole - and was on Anastrazole for 5 years (stopping shortly!) it had the least side effects for me xx
take care & all the best xx