I've found it similar to learning to play an instrument. It all seems clumsy at first, and you are trying to think of too many things at once, and find some kind of rhythm, and then gradually it all comes together, until it becomes second nature, and then all you have to do is perfect the individual songs. A bit of an odd analogy, but that's how I felt.
Easier said than done, but try to stay relaxed, don't over think as it can make your movements unnatural, have music or something in the background to slightly distract your self (works for me anyway). If you aren't already, try the airbrush tutors exercises, it can be frustrating, but most of us have been there, so you have all our support, and once you have those exercises licked you will have all the skills you need to be able to amaze yourself with what you will be able to paint!
