I am late, but I will answer:

In short, I have one strange fetish. I like women 37-40 years old who look younger than thirty years old and care about themselves. This is the ideal of female sexuality. And this excites much more than a beautiful girl aged 20-25, for example.
Am I the only one or is someone like that?

You are so much more than you think. And for this you have a great human thanks from a young looking 40-year-old woman who likes boys younger ;)