The one thing that has kept my wife and I together these past 6 years as I wrestle with the trans-beast has been the most times difficult, always brutally honest and open communications we make time to have. Sometimes even having to schedule them since brutal honesty is not a dump and run situation.
Brutally honest also, if not primarily, includes your internal dialog. Yes, having the T-Bomb dropped on you is a LOT to take in. This is true for about every SO. It was even true for my wife who knew for some 30+ years I had gender issues and even stuck around the house the days I needed my escapes from maleness. (And yes, I still get "I did not marry a woman". Which is totally fair of her to say and feel ). Same for your SO. Life in general is a balancing act, a constant juggling of often times conflicting needs and wants. A full social transition is not an easy undertaking by any means. In many ways it is even more difficult for an SO as they know they have the option to cut and run.