Symptoms 3 years on

Hello there, I’m coming up for three years into a diagnosis of HER2 neg, pr/er pos breast cancer - stage 4 since diagnosis, no mastectomy, but taking Letrazole, Palbocilib, Adcal and, as long as my white blood cells are high enough, a Denosumab injection monthly. I also have a morphine patch due to a painful spine with sclerosed metastatic involvement.  On the face of it I’m doing ok, disease remains stable according to CT/MRI scans, but I’m having some symptoms which I find more difficult to deal with. Getting up in the morning is painful as it feel as though all my joints have seized up during the night and I constantly feel tired/fatigued. Does anyone else experience this feeling of locked joints? Obviously, as an older breast cancer patient I don’t expect to feel as young as I did, but this joint problem is a new one and quite debilitating/upsetting. Any thoughts would be gratefully received.  Thank you!