Hi NB
Horrible though it may seem it may just be that you are one of those unlucky women who don't get a lot of results from hormones. My first GF, for example, a natal female, never developed a bust at all. Sadly if so it is unlikely to be changed much by altering the delivery system so alternative methods may be needed to achieve the desired figure.
But there is one little thing which you should probably also investigate - if you are taking estradiol-valerate, which many people in the UK do, then you should try the alternative formulation of estradiol-hemihydrate because a very few women (about 1 in 100) lack the ability to properly metabolise estradiol-valerate.
The alternate hemihydrate formulation overcomes this problem. So it is worth trying that if you haven't already done so. It's available in both pill and nasal spray form, but as it is considered by pharmacists to be largely interchangable with valerate you do need to get a prescription which specifies Hemihydrate, (and in my experience it also pays to check what you have been given when the pills are dispensed.)