Thank you @iserbrown,
I admire you being able to put up with side effects for 10yrs, that's amazing. I have been told I need to be on them for 5yrs by my GP but my oncologist seems to not be as concerned! I am willing to keep going on Letrozole if I knew the side effects would settle down, or try another one.
I am not able to take Tamoxifen as I have Factor V Leiden blood (aka. sticky blood prone to clots) and have had many uterine polyps removed. It's a shame as I know a friend who has done okay on that with no side effects at all, I was hoping I'd be able to try it to but my surgeon warned me it was not an option.
I will persevere and hope changing around the AIs or having a break for a few weeks will help :)