If an AI is recommended (because your body will still produce some oestrogen), and if it’s the prospect of unpleasant side effects (I am assuming joint pain) that is the main reason for not taking an AI, have you considered trying it and stopping if you get side effects? I have taken an AI for ten years (finished last May, hooray) and I did have some side effects but no joint pain or aches, no
menopausal symptoms, flushes etc. I experienced some loss in my bone density (but note ten years, not five, and I was nearly 20 years older than you when I started, which makes a difference, there’s a natural loss operating too!). Side effects usually start quite soon, so you can make a decision before anything becomes too difficult. Like chemo, knowing any individual reaction to an AI is tricky. Best of luck whatever you decide.