There are several ladies with an endometriosis diagnosis who have to make decide to use or not use HRT. There can be pros and cons for both sides and it can depend on the knowledge of your doctor.
While estrogen can fuel endometriosis, it is also essential for overall health, especially the younger you are. So, when considering the endometriosis risks of ERT, one also has to consider the health risks of no ERT.
Also, endometriosis can create its own supply of estrogen, no ERT or ovaries necessary. Thus, going without ERT doesn't always keep endometriosis at bay.
What some doctors prescribe is a combination of both estrogen and progesterone (or progestin). This way one can receive the benefits of estrogen while hopefully the progesterone/progestin keeps any endometriosis at bay.
There is no simple answer and each women will have her own pros and cons to consider. You might get a second opinion and talk to your GP before making a decision about what might be best for you!
You are also welcome to check out the Endometriosis Support forum and see what the other ladies there are doing.