@Trikki2 I'm on Letrozole rather than Tamoxifen but the side effects of joint and muscle pain are similar. When asked to list the sites of the pain I joke that my left shoulder is quite okay - not so much of a joke, really. I'm not sure that I do manage the pain. I live with it, and in spite of it, and it is exhausting. My medications range from panadol to panadeine forte, depending on how bad it is today, and a trusty wheat bag for my legs at night. Sometimes I go to bed early simply because laying down is the least painful position. For one blissful week, I took prednisolone, and the impact of that alleviated much of the pain for quite a few weeks afterwards. Unfortunately, any more than that is likely to have dire effects on bone density. It has also brought on arthritis in my hands and neck, signs of which were already there but unlikely to have had any real impact on me for years if not for the Letrozole.
Lots of people advocate exercise which I try to do but the effects are hard to anticipate. Sometimes it really helps, sometimes it can make the pain worse.
I'm off to see a rheumatologist in December (6 month waiting list to get in) and if she doesn't have any good answers, I think my next port of call will be a chronic pain specialist. The gap for these people is horrendous - I got off quite lightly in the financial stakes during active treatment with regard to what I had to shell out (the fact that I couldn't work is a different story) but the dollars are adding up for dealing with the aftermath.