I've been reading a bunch on different types of estrogen and the various manufacturers as well as the advantages and disadvantages of each. I have not finished that reading. However, there can be differences between the effect of each specific type (which is why there are several types) and the effect of each delivery system (again, that why there are a number of those.) You are on pills. Are they the same brand name that you were on before? Is it the same dosage? Is your diet the same and are you taking them at the same time you did previously? Also, metabolism changes as we get older. Talk to the endo.
As far as frying estrogen receptors, I don't think so. There has been some literature about increases in the number of specific receptors depending upon the specific hormone the body is exposed to. For example, estrogen can cause the proliferation of estrogen receptors. I do not know if the T receptors decrease in number as I'm not done reading about that either and it's complicated as there are different types of both T and E receptors. However, for practical purposes, you may be starting over and not picking up where you left off.