Guidelines advise treatment should be individualised however there is often pressure on GPs from the health board not to prescribe above 100mcg of estradiol.
Unfortunately healthcare has always been rife with misogyny and this is yet another example. Funnily enough the same beliefs about restricting and rationing treatment don't seem to apply around treating other conditions - a diabetic is never told sorry, that's the maximum dose of insulin you're allowed.
Higher doses of estrogen have not been shown to increase the risk of endometrial cancer for two main reasons
a) It is the amount ABSORBED that matters, not the amount taken. For example one woman can use a 50mcg patch and achieve a high plasma level of estradiol, and someone else can use the amount you do and have barely above menopausal levels on a blood test.
b) as long as you are using adequate progestogen to protect the endometrium, which can be assessed by ultrasound, then there is no increased risk.
Unfortunately however many of those who need a higher dose to achieve therapeutic treatment do end up having to self fund this.
Have you had any blood tests done to assess absorption?
Another thing to consider is that some people just don't absorb well through the skin, and oral estradiol at doses considered standard can do a much better job than tons of patches and gel in these individuals.