Confidence plays a big part and at some point you have to just accept that no matter how well you pass there will be people who will question your gender. Be proud of who you are and remember that the best reaction to anyone questioning is usually a smile.
I think you live in the same city as I do, assuming this is correct I can say that from my experience it's one of the most open and accepting places in the world to be trans, I could not have asked for a better place to live and work in.
I've been full time since June and even though at first I was very nervous things have gone very well, from the start I decided to not wear a wig or any artificial padding, etc in my daily life since I think that would have made me feel uncomfortable. In my case I went full time before starting HRT because at the end of the day I figured I needed all the practice and experience I could get and honestly I did not want to wait for months or years.
Based on my experience I think voice, body posture, walk and movements play a much bigger part than anyone realizes and these are all things you can work on right now, HRT has little or no effect.
Also remember that girls don't wear skirts and heels every day, it's OK to be casual and comfortable