You need to find a way to complete your backswing. If you do not complete your backswing you do not have the ability to whip the club and compress to the ball on impact or whip the club effortlessly through the golf ball. To be able to whip the golf ball you have to be planted on something solid which is your front foot.

Allow the forward heel to come off the ground. In order to feel the full back swing, from you left-handed swing, the first move down is to plant the forward heel with pressure. Don’t slide off the heel. Turn and let the forward knee come behind the ball and feel like you are falling through the golf ball and your foot should be planted well before you hit the ball. 

The swing sequence is turn, plant and whip. Feel like you are tossing a freesbie or chopping a log using an axe.

Once the right heel is planted, it does not move away from its present position in the golf swing. 

The separation between hips and shoulders happen on the downswing. Once the right heel is planted, there will be a separation of the legs that will coil up the muscles in your back which will give you the slingshot effect through the golf ball.