I’m sorry but Fluttershy in “Filli Vanilli” is picturing whatever I am and why am I always on and off on pony music.
It’s something all aspiring musicians think about I believe. When you start having a big following or make something for a particularly large fandom, the fear of many people judging your work is there, and it’s a very real fear. I sometimes get this with the Yuri/SonoHana fandom when I make something new, wondering what they’ll think of it. Granted, it’s a smaller community, but it’s certainly a bigger following than what I had previously.
The best way to deal with this is, as you said, taking baby steps and show the world your passion for singing and songwriting. There will be some hardships for sure, but you live and learn from those, and move on. Keep making the music you love, and good luck on your upcoming performance!