Dear Pugs4life,
Kudos to you for being willing to understand their situation better. (I'm referring to your husband as "they/them" because some folks are deeply affected by gendered pronouns. The correct one can bring on a euphoric feeling (like a new mother being referred to by other as "momma.") and the wrong one can sting (dysphoria)).
EDIT: wow, I just read the post above regarding your use of "she/her" pronouns. That's a wonderful gesture.
As a lifelong troubleshooter and fixer of things, I tend to try to get ahead of problems before they occur. I'd like to share a bit of my story and a few thoughts...
Simply put, I always thought that being a girl would be better than being a man. I was born in the 60s, so I really had no idea what to do with these feelings. The first time I saw a trans person, I was riveted. It was thrilling. I didn't understand why. With no public-facing outlet for these feelings, they morphed into something akin to a fetish. The thought of transforming into a woman gave me a thrill that caused a physical response.
Guilt ensued. Guilt, and the strong feeling that I was a pervert, a fake, an *impostor.* Impostor Syndrome happens to athletes, musicians, scientists, and so on. I just assumed I wasn't a "real" trans person; I was just a guy who wanted to be a woman...like I thought about it every day for 30+ years. Funny thing is, I figured most guys felt the same way at one time or another. Any explanation made more sense to me than the idea that I wasn't really the man I thought myself to be.
When my "egg cracked," the realization of what I really was (a trans woman) came pouring out of me. I'd been with my partner for almost 10 years and I shared my feelings with her. She reacted with kindness and understanding but I knew that she felt betrayed. She figured I should have told her, that it was unfair to her. She put a chunk of her life into our relationship and I'd pulled the rug out from under her.
How did we survive? I went slow. I'm still moving very slowly. We're in our 50s and it takes time to adjust. We're still partners (got married *after* I came out to her) but our relationship is less traditional than some. Sure, I still fix the cars and take care of the house, but she knows I'm not longer a man; I'm something else. I have an "X" gender marker on my driver's license and passport.
Anyway, my point is that I got lucky. I'm lucky that I paired up with someone intelligent and reasonable enough to be able to work through these feelings without wanting to burn it all down. I'm lucky that my transition is moving slowly.
Others here haven't fared as well. One (trans) woman I know started hormones, dressing (presenting) in public as a woman and had surgeries in very short order, and the strain was more than her wife could take. Several others I know were met with hostility from a wife who felt she been tricked and betrayed.
Your spouse is likely bursting at the seams. The realization of who/what we are can be like a burst dam. They might be *aching* to experience so many things they denied themself. I started hormone therapy a few short weeks after coming out to my partner. My body started changing immediately. It all seemed very fast, but then again, I wanted to take my girlfriend's birth control pills when I was 20 years old. The outward-facing parts of this seemed sudden and impulsive, but the feelings had been simmering for many, many years.
My hope for you is that they're able to go as slow as you need them to, giving you time to process all of this, and that you continue to work to understand what they need and who they are, and to give them permission to experience things long denied. Most of all, you must understand that they never meant to hurt or betray you. It's likely that they just failed to understand what they were going through.
The fact that you're here with us speaks volumes about your love for them, your emotional maturity and your desire to do the right thing. I'm filled with hope for both of you.
