I do not find the need to create a fictional character with my features to feel better. I don't need people to accept me as pretty or fawn over my features, I need people to not treat each other differently because of their look. But I realize, even people's perception of fictional characters is heavily influenced by their appearance (with the real life biases attached), and especially because "they're just fiction."
I remember reading together a manga with love rivalry included. There was a love rival character with tanned skin appeared (as as opposed to light-skinned blonde MC) when a classmate said "Ew, I hate her! Her skin is so dark and she thinks she is pretty." She never ridicule me or say I am ugly, but being a person who was ridiculed for not exactly light-skinned enough, I just sat in silence.
Some of early comments in my art journey also shaped my character design. "Why is she/he (brown/curly/ugly/freckled/have cat ears/looks Indian(?)/dresses like a slut/etc.)?" For now I can brush them off and not care, but as a kid being told that by adults, it felt like I did something wrong. I felt like I should only draw something they deemed pretty.
Until I broaden my horizon and see other (foreign) artists and characters (with how people respond to them neutrally or positively). Then I thought, "Okay, I can try that."
For now my rule is, if it fits the narrative, aesthetically coherent, and convenient to draw (most important), then that is my characters' design. I no longer give a rat ass whether they're a bishie or are waifuable or not.
There is a character, though, I designed against what deemed as conventionally attractive, because he shared a name with heartrhrob male leads for local popular series, and I thought it would be fun to kind of subvert because I like the name.
TL;DR: not insecurity on how I look, but rather how the character is perceived.