One of the most common things one sees in any instruction thread is attempts to "treat the symptom" rather than to "seek the cause".

You mention two things:

1. that your right heel is grounded at impact; and
2. that you swing to the left.

It is probable that 2. is the result of 1. i.e. if you are rotating through the ball and your right foot is grounded then the natural tendency is to swing left whereas if you were up on your right toe at the end of your follow through you'd be swinging "down the line and getting the extension naturally".

The most likely cause of the heel being down is a slight reverse pivot and instead of turning your shoulders away from the ball on the back swing you may be swinging under your chin with the result that there is a slight tendency to "fall back' on the downswing leading to the grounded right foot.

My teaching pro taught me to get about 60% of my weight on the right foot at address and then to feel that my left shoulder was above my right knee at the top of the swing. This allows me to release through the ball much like a baseball pitcher moving on to his left side.

Hope this helps.