Absolutely not. I'm in my 3rd year and my face didn't atart constantly looking femme to me till about 2.5 years in. There's many more changes that come later! Cis-femme puberty starts roughly around 12 and goes until 25-ish!
The terms "fully developed" and "most" are doing some legwork there. Puberty begins and ends at different times for everyone and statistical averages have been shown to change over time.
If you are talking about just secondary sexual characteristics then sure but people do still continue to mature physically. Just look at people when they were 18 and are now 25
I think this is more dysmorphia than dysphoria. The good news is that all women feel this, many just as strongly as you. I would look into resources for women with body dysmorphia. The strength of the dysmorphia isn't tied to how attractive the person actually is. Plenty of supermodels and attractive actors get convinced that everyone is lying about them being hot. Your self view is unreliable right now. A big part of dealing with dysmorphia is making that view more grounded.