Please don't beat yourself up! I also had severe side effects and stopped taking them at the 4 year mark. My understanding also is that the most benefit in my case was in the first three years of taking an AI. I nearly burnt my house down because my memory got so bad I forgot I left the griller on in the kitchen and went outside. I also could not toilet myself properly because of the stiffness in my elbows. I would mix up my thyroid med (my thyroid packed in after the chemo, radio and one year on AIs) and AI and take the wrong one, and I also lost balance a couple of times and fell over in the street. I probably would have been dead by now if I continued on with an AI.
Will my cancer return? I don't know! What I do know is that I have a better chance of staying alive not remaining on an AI that was causing me so much pain and not to mention the insomnia I was going through. I ended up seeing a psychologist not knowing whether I was "arthur or martha".
For what it is worth I also started to feel better once off the AIs, and wondered should I try them again. The oncologist said no! After what I went through I know I made the best decision to call enough is enough, with the blessing of my oncology team. Besides, even though those that remain on an AI for 5 to 10 years, can still get a recurrence. Give yourself some grace and love yourself, because you know how much you went through, through no fault of your own. Take care and enjoy your life. xx