Jilleann, I recommend that you read Jennifer Finney Boylan's book, "She's Not There, A Life in Two Genders" ISBN 0-7679-1404-X
It is a well written book. Ms Boylan, formerly Jim Boylan, a novelist, writes about her struggles, her marriage and how it happened that she and her partner stayed together. Ironically, reading the book made me realize a lot more clearly why many marriages end under the influence of transsexualism in the family.
I've been really lucky so far and am still with my SO and I know that this could change in the future. I asked my wife to learn about what transsexualism is all about, she finished reading "True Selves" by Mildred Brown & Chloe Rounsley a week or so ago, so if she did decide to strike out on her own she would be making an informed decision, not a purely emotional one. It took her a long time to reach a point where she could read it without becomming upset, many months. I didn't remember if you mentioned going to a therapist but that would help too. My SO has gone to see mine for the past three sessions and I think that helped her too.
helen