As it happens I was watching a documentary about body dysphoria the other day and how hard it is to deal with in every day life. I cant imagine what it would be like but to be honest feeling at home in my body is something that I take for granted. I know you said not medical intervention, however my advice would be to see a doctor and they can give you hormones to change your physical appearance and all the mental support you need. If not then try talking to your best mates about it....if they are really mates they will support you and keep you going.
Apart from that I doubt that you can do much more than to think of yourself as whoever you want to be. Btw I appluade you for being so strong. Keep going strong and life will work itself out eventually.