Just feeling so sad when I saw your work and then look at mine.

When improving on a high level you always take small steps, don't you?
And maybe you reached a point where improvement is no longer possible?!
on and off I've painted for around 10 years, never give up and keep positive start small and think basic.
Use a rule of 5 main colours per model, base, wash for shade then drybrush for highlight, get that nailed then try doing layers, crack layers start blending, etc etc.
Small steps but get the fundamental parts right and your painting will always look good no matter how far you go with the detailing, some guys on here have the detailing part nailed to a tee and seeing that keeps me motivated to improve.
I read an article years ago that said "you never stop learning" and since returning to miniature painting that has never been more true.
Practice, practice and more practice and you will get there I promise, my first model was all yellow with a green hat.
Never feel sad, just look at it objectively, think how does he do that?, how can I copy that, look at reference material as you paint, I always have a white dwarf out or a book with colours schemes etc.
If your really struggling post a thread with what you want to learn and we will all help you reach your goal.