Hitting the ground before the ball can be one of the most frustrating feelings in golf.
If this becomes a pattern, not only are you losing distance, but also confidence.
The first step to fixing the problem is a proper diagnosis for why it's happening, then a clear mental picture of a quality swing, followed by structured practice.
The following concepts are shorts and simple...but that does not mean they are easy. It will require work and patience, but the feeling of solid contact will be worth it.