Wow, I had never thought about the stages of grief - but looking back at my own situation relative to my partner, it unfolded exactly that way with him:
Denial:
When I first told him I knew something was seriously wrong with my sexuality or gender, and that being with him as his female partner was just too much for me anymore, we decided to just be best friends who live each other. Then, awhile later, I came out to him as transgender. He denied that it was possible. Vile transphobic jokes made in passive aggressive ways. He went of his way to assert aspects of femininity in me whenever possible.
Another form denial at this time was the pretense of relationship where we still got along with each other same as always. He was there for me in a major way at one point in our lives, so I let a lot of the above behavior slide as a weird undertone to what was otherwise a great friendship built on years of being together.
Anger:
But - all this denial was a mask for anger. His anger at 'decisions about his life that were made without his approval,' that I single-handedly changed his entire life without his permission. The 'jokes' about me being trans turned into outright insults. I wanted to move out, but was not yet in a place when it was possible. He knew this and understood it, and we both felt increasingly trapped. The anger boiled over and was sparked by pretty much any sort of disagreement, by both us.
Bargaining:
Then, out of nowhere, it was like the dam broke. We had a really long talk that went all night and into the morning, and both of us cried and we hugged, and we talked about how much we love each other. But we were still just friends - we slept in different rooms, etc. Then we started having a physical relationship again. I had started T by the point. He suddenly found himself in an awkward position.
The bargaining came in with how he justified it to himself, "only until T the effects really show, etc etc" then it became..."ok, but you can't have facial hair,". "I will never call you by male pronouns." "I still don't think this is a real thing." He would get uncomfortable when we were in public together and people thought he was my older brother, but he would still be happy for me that I passed.
Depression:
Even as we were better than ever, he straight up got really depressed and slept all day for a couple of months. He had no interest in anything but sleeping or video games. We were great, but he just lacked interest in anything else in his life. During this time, he started becoming more supportive. Still made jokes, but they were in context - like someone teasing a kid with a changing voice, when my voice would squeak, etc.
Acceptance:
Time and acceptance I think pulled him out of his funk. We had our roommate move out, so we could live together as a couple again without a third wheel. He just got a great new job, and I told him, "I'd rather you not mention me than refer to me as female." And he said, "I will call you my partner (male name)." Which is a huge deal for us. I couldn't believe it when he said that.
He has publicly defended trans people, makes understanding remarks, gives me tips about passing better -everything is so much better.
I should say this took a really, really long time. The first break up conversation was at the beginning of 2011. We are just now great as of very recently. Also, we have now lived together for 10 years.
So, have patience.