i was uncomfortable. mostly because it was new, felt different and i had gone by that name online so i associated it with being ashamed, even though i loved the name. there will be slip ups, and you have to remember that they probably aren't doing it on purpose and you WILL know when they are doing it on purpose. just imagine knowing a chair is called a chair ever since this chair came into your life, but then you go to a different country and someone told you no, that's a table. you'd have troubles calling it a table after that, wouldn't you? because you knew it as a chair before, but now it's called a table. people who care i think eventually get it right and stop slipping up. when my mom would slip up with my birth name, i'd be like "who?" or i would straight up tell her i wouldn't answer by that name and ignored her until she used the right one which was usually a minute later, or even my brother would correct her. i think she just hated the fact i'd actually ignore her, but it did work. my relationship with my mom is different and i'm older, so it made it easier for me.
the point is, you can't expect everyone to switch right away. my aunt when she would mess up would be like "i've known you for 22 (at the time) years as this name, now i need to change it" because they associate who you are with that name. you can't just expect everything to change over night because it is all a process. the only person in my life who switched right away, no mess ups, etc. was my brother. he didn't question nothing, just accepted it and i am very thankful for that because it made it easier when everyone else screwed up. when you start T, it will be a process and if you get surgery, it's a process. everything with transitioning literally takes time and i know that it seems like everything takes FOREVER to line into place (even the little things), and sometimes it does but when it does? it's a great thing and you will (hopefully) realize how worth that wait it was.