The first time I tried to transition (a decade ago) I had a fear of telling certain people. Doctors, parents, and other family. I came out privately to a few people I dated, and the bad reaction I got made me feel less inclined to tell. At this point, I am 100% ok with telling everyone. It's not always a topic I feel like discussing with people who are misgendering me.
I understand what you mean about your voice. When I hear myself talk, I hear a female voice. It's not as pretty and enchanting as I'd like it to be, but it definitely doesn't sound masculine to me. Somehow, I get misgendered on the phone often.
Of course you think like a girl, because you are one.