Welcome aboard hun!!!!
For me, one of the best things about having found a therapist, is he's really been helping me continue to find myself. And well, as for losing yourself, I don't so much think its that you lose any part of YOU but freeing up what was always there but neglected for so long, maybe? I don't quite know how to describe it.
But yeah, its okay to be afraid of what you may become, its only natural. But what the difference is... is that you need to decide what to do with that fear. For years, personally, I destroyed myself, telling myself that its not right to feel masculine. Its wrong to behave like a man. And finally, when I couldn't take it anymore, because I'm not the type of person to just give up, I researched the hell out of how I felt and looked. And decided to make a change. And as I've done that, I've realized, I've only grown as a person. I've learned to love myself more...
Long story short, I think that's how eventually you will come to feel too. (And now I gotta run, daughter's making a splash zone)