Being unsure of who you are and being unsure about transition are, in my view, two slightly different things, albeit with a common starting point.
The best advice I can offer is to look inside yourself, use some introspective techniques like meditation... look at who you find there, and notice how being that person makes you feel. Your sense of identity is something that's just there, no matter what you decide or don't decide to do about expressing it. And going with how you feel, intuitively, rather than the analytical thinking and dissecting of everything, I think, leads to a more grounded, surer acceptance of who you are.
In my own experience, being more in touch with your inner self tends to eliminate the "What if this isn't who I am?". That's just a given. The "What if I can never express who I am?" Tends to be harder to remove, since that's reliant, to an extent, on other people's perception of you... and not entirely within your control. But again, if you have a strong core self-image to fall back on, it makes things easier. 🙂
