ruined model

Here's a quote from the Simpsons. I think it was when Bart was learning to play guitar:

"I wasn't good at it right away so I gave up"

Why not buy a few cheap kits and literally throw them together to practice painting and goof around with flat coats. I use testors lacquer flat over future. Light coats it works amazing. 

Had the same problem:

1.  Shoot the whole thing with Future again.

2.  Thin down your Polly-S clear flat 50/50 with Windex (I use clear Windex).

3.  Re-shoot the flat in very light coats.

What kind of flat clear, what did you paint over and how much effort are you willing to fix it?