Hi rockit,
Welcome to Susan's!
My story is somewhat similar to yours and to Adrian's, except it's from the MtF side. I cannot say that I have always been certain about my gender, about each aspect of my appearance or about all the steps involved in transition. Instead, knowing what exactly I would want is part of an ongoing process of self-discovery. For me, it's been just 2 months of conscious questioning so far, although it is the result of years of confusion and subconscious questioning, and I can already see changes in my attitude towards different aspects of transitioning, not just physical but also social like pronouns and stuff.
As others have said, talking to a therapist about all this will help a great deal.
Take care
Cindy