Clutch
 

Basically, I sat in my car and my left foot went in behind the clutch and while pulling my foot back forward, I dragged the clutch with me and now it has some play in it and before it used to be stiff. 2003 mustang Gt.

Congrats! You just accidentally (literally) tripped over how to adjust the clutch...sounds like it needed adjustment.

Hahaha. So how exactly do I adjust it myself?

You already did...by accident. Up under the dash, there is a toothed/ratcheting mechanism (quadrant) for clutch adjustment. When the clutch pedal gets to the point where there is little or no play, you pull up on the clutch pedal, and it jumps to the next tooth, which gives you back some free-play at the top of the stroke.

https://cimg7.ibsrv.net/gimg/www.cmo...17b3d50eca.gif

Hehehe...he said stroke..

That's kinda funny. My first new car bought out of university was a 1987 Tempo 2dr. Cable clutch with the same method of adjustment.

Quick word of advice if you ever have your clutch replaced and choose to reuse the original clutch cable and clutch adjuster. Make sure the tension on the clutch cable and fork is released by pulling back on the peddle and manually setting quadrant locking pall as far up the quadrant as possible.
It is believed that during a clutch change in my car prior to my owning the vehicle this wasn't done and the clutch adjuster pall was left at the clutch adjustment setting on the quadrant for the old clutch. When the quadrant was reset to set proper tension on the cable and clutch fork for the new clutch and bearing, the quadrant was pulled too far, jamming the adjuster pall against the clutch safety switch. This limited how far the peddle could travel to release the adjuster pall and prevented the adjustment pall from releasing from the quadrant. The only way I was able to adjust the clutch was to carefully reach up with my hand to release the pall from the quadrant while holding the peddle in the pulled back position