Before you start panicking and think you have contracted some vicious disease, rest assured that there is a cure for the shanks. There are only five causes for a shank. We just have to determine which one is occurring to produce this type of shot. First off, a shank is simply impact on the heel of the club rather than on the face. Somehow the heel of the club moved closer to the ball than intended. Let's examine the possibilities.
Once you have established the cause or combination of reasons for the shank, you need to simply eliminate it / them from your swing. Remember that if you were getting too close with the heel, you need to be working to get the heel farther away from the ball at impact. One way to quickly change this is to put a tee on the inside of the ball and focus on hitting the tee rather than the ball.