[NarunapyCalry]

Try this - use a bigger number (more syllables) to get a longer count on any part of the swing, use a number like 6 hundred and 15. Works like this 'six hundred' going back to the top of the swing and then pause at the word 'and' then 'fifteen' coming down hitting the ball at 'teen'. If you want to slow the backswing even more use a longer number like 1700 to start back with 'seventeen hundred and fifteen'. If you want your downswing to go faster then use a shorter second part, like 'six hundred and five'. Using a longer number sound like this eliminates the chance of counting '1,2,3' too fast which defeats the purpose, the correct timing is built right into the length of the sound needed to say the number to yourself. A really slow tempo would be to use something like 'twenty-five hundred and thirty eight' takes longer just to say it to yourself. Try out different length sounds for both back and down swings until it seems right to you.