Emmy,
First off, it seems you are getting over stressed and worried here, which will do nothing in helping your migraines to go away. Everything will be alright, take some deep breaths, find some ways to relax, and get both your mind and body to calm down. I know I posted this already to you, but, are you getting enough sleep, are you eating a healthy diet, etc.? - Look back on my previous post- Being off of HRT for a period of time will not completely reverse things and any loss will be regained quickly once you start hrt again. Right now, when you are stressed and you are in pain your body will really devote very little to feminization,rather choosing to use its resources for managing the stress this is causing. Secondly, when was the last time you had an electrolyte panel done, especially being on Spiro? Your potassium and sodium levels may be off, which could definitely cause migraines to erupt. If you look at many of the migraine prophylactic medications they regulate the sodium ion channels, which happens a lot in cellular (especially neuronal transmission), there is a reason for this and any investigation into migraines should include your serum electrolytes. Your best defense here is to drink a lot of water, 2-3 liters a day. Potassium and sodium are very closely related an increase in one will often cause a decrease in the other and vice versa. Estrogen would be quite rare to cause migraines, but you never know. As a medical professional I can provide you with more suggestions to work through with your primary care provider, but rather do it in a PM format, as such PM me if you continue to struggle.
Meg