What in the world is this crazy pain in the front of my leg when I put my foot down?

This is a condition called Shin Splints. It's an injury to the front of the outer leg that results from inflammation in an injury to the tendon (posterior peroneal tendon) and adjacent tissues in the front of the outer leg called overuse injuries.

SYMPTOMS: Pain in the front of the outer leg below the knee next to shin bone (tibia)
Pain often occurs early in the workout and toward the end of the session.

CAUSES: Sudden increased distance in running or intensity of a workout schedule.
Tight Achilles tendon or weak ankle muscles often implicate the development of shin splints.

TREATMENT: Relative rest is successfully utilized to restore pain free level of exercise again.

The approach includes:
1. A change in workout (cycling or pool)
2. Ice
3. Rest
4. Antinflammation medications (Advil or Motrin)
5. Stretching Exercises
6. Change in footwear & a gradual approach to running activities