Oral estrogen is estradiol. Better is ethinyl estradiol as it's more active but it would need to be as a patch or injected. However, the patch is expensive, can cause skin difficulties and injections aren't fun. Most forms of estrogen will also lower testosterone so once there is enough in the body, estrogen will help further lower testosterone.
A rather odd option could be depo provera. One injection each month in addition to your current meds. It helps lower testosterone and as a derivative of progesterone, there MAY be some additional feminization effects.
My doc targets estrogen to be between 200 and 400, testosterone less than 50.
Talk to the doc.....