I understand that secondary lymphoedema (caused by removal of lymph glands because of cancer treatment) can occur up to fifteen years after surgery! Which seems pretty poor to me! Imagine if you had recovered well, thought you were clear and then got that sort of postscript so long after the event.
However like most, I got mine much sooner - 7 months after surgery I noticed the slightly swollen wrist. So far (3 1/2 years) it's OK. I wear a compression sleeve and "hand" but not at night. I do my arm exercises daily (it's about 5 minutes so no excuses), massage frequently, elevate when I remember and have treatment by an excellent therapist about once every 4/5 weeks. Fluid retention was significantly reduced in the first 3 months, and has been maintained to date - no discomfort, no hardening of skin, or any of the other undesirables. Which does make it easier to just forget it most of the time. I hope yours settles so you can do the same.
My "bionic hand" gets a few strange looks, but I can think of much worse things that many people have had to contend post bc with so no complaints from me. I would have whipped my lymph glands out too, several looked very suspicious - as it turned out only one was malignant, but it was a perfectly reasonable thing to do.
But I am grateful I don't live in Queensland - hot steamy weather and a compression sleeve leads to very bad language!