you answered yourself pretty much mariner (but still I can't swing from the inside if there's a ball there (no problem without a ball)
that is one of the biggest problems with people struggling with there swings practise swings are great as soon as they put a ball the all goes wrong. you have to remember your not hitting the ball your swinging thru it, you shouldn't be thinking of the ball at all. try this tee up 10 ball in a row about 4 inches apart, get set up just out side the first ball and make 6 or so perfect practise swings then without stopping step up swing thru the first ball keep going right down the line with all 10 balls don't worry about where there going just work on the feeling of swing thru the ball with a nice balanced finish. try it you ll like the feeling believe me