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I had the exact same situation as you, only I started my third year of a four year course. I introduced myself initially as female to the first years, but had Harry as my name on Facebook. Two girls from the first year asked me which I preferred (the one of them had guessed), so I told them. But I didn't tell anyone else, not for a long time, and I switched between how I would introduce myself. It was awkward and confusing, but I was just way too ashamed and scared to officially tell everyone else, but because I hadn't told them, I felt like I didn't deserve to have anyone use male pronouns, so on and so forth. Eventually I told my housemates, who are also my closest friends, and after my first appointment with the doctor I told the rest of my friends. I followed it up with telling the staff, who switched in class, and everyone else followed suit.
Now it's all out, and everyone uses my male name. Some people still use female pronouns, but they're twunts and just look stupid with everyone else using the right ones. Even though I had a lot of trouble with some friends who were really horrible and belittling to me in front of everyone, they eased up with time. So, I hoe it all goes well!