kayeb - you will need to use progesterone to induce a withdrawal bleed. If the bleeds are a problem you could consider a Mirena as this should control and eventually stop all bleeding - you can then use as little or as much oestrogen as you need. Evorel 25 is a low dose and could take longer to reduce symptoms but it could be enough in time to control meno symptoms - an increase to 37.5 or even 50 at your age would be absolutely fine and in fact, to protect your bones, could be beneficial. Your Breast cancer risk at 50 is very,very low so don't worry - it's when you get to 60 there might be a slightly increased risk.
With HRT it is about finding the right regime for you - so very much trial and error. DG x