When you sprint, you should not think about clawing the ground. This will cause a breaking action and result in overstriding, which could lead to injury eventually.
Sprinting is not something that you should over analyze really. Paralysis by analysis! Over thinking while you sprint is just going to make you confused and frustrated. Just stay relaxed and focus on maintaining your posture throughout the sprint cycle.
It is something that you must do over and over, this doesn’t come over night. Just like staying on the balls of your feet, it may be you just aren’t strong enough yet. Keep at it. Get a video maybe, that will help out a lot more for people to analyze you.
A skips, B skips, basic marching drills are good places to start. Sprinting is an up and down motion, not front and back.