Airbrush help!

Hello, I have been modeling for awhile but am tereible at air brushing. I am currently building 2 Hasegawa 1/48 F-14's. I have screwed the first one that I painted up while trying to paint "lighter tones" in the middle of the panels to get that authent F-14 look. Here's my problem: any time i try to paint with a very thinned paint, it comes out inconsistent and basically like water all over the model-never like the way that the youtube how-to videos look. I use tamiya acrylics-thinned with tamiya acrylic thinner, and have a cheap (ebay) airbrush and compressor. Is the solution to upgrade to a nicer airbrush? is the fact that i dont have a regulator and the ability to turn down the air pressure the problem? Or is it the paint that I am using? Please help! I would like to try salt weathering for the first time on these models and if i dont figure this out, they are going to end up look like 2 very plain F-14s. Thanks!