Hi @Glynnis. Yes to the Letrozole aches. Like you, sometimes Panadol Osteo works, sometimes it doesn't. When it's the latter I try an anti-inflammatory in combination with paracetemol and that can be effective. When all else fails and the pain is truly awful, at night I take an Endone from my carefully hoarded stash.
You could maybe try a bath before bed with some Epsom Salts, or one of those Radox muscle soaks.
However I am not a doctor! So it's best to have a chat with your GP about what and when to take. K xox