You could try Acetone, it may soften the paint. Otherwise, sand it back down, at least to the primer. I used to use K&B or Hobby Poxy paints with my compressor system, but in recent years, I generally use Rustoleum primer and paint, and have no trouble with it. (Spray-can versions). I have heard of probems if you paint, then re-coat within a day or two.....supposedly you must wait for the first coat to really chemically cure all the way down to the primer before applying another coat. I shoot a "dust coat", wait maybe ten minutes, then a "normal" coat, reasonably wet, then leave it alone.

Clair