This morning I drove a few blocks and the car was warmed up. I parked and was gone for five minutes. When I came back, the car would start, but was idling very, very rough.
The yellow engine light was flashing, there was very little response to the throttle, and the engine sounded horrible when revved. I did not even try to drive it. I knew it would not move.
I am having it towed tonight, but does this sound familiar?

 

Yes i do, your coil packs crapped out! I know this because this happen to me last month. Easy do it yourself fix! Save yourself some money and get aftermarket coil packs. Mazda coil packs are overly expensive.

*Coil packs usually don't give you warning when they go out, either they work or they don't and when they do go out ,you get symptoms that you mentioned above.

 

^LS2 swap FTW!

 

Started it up last night and it ran fine! Very strange.
Check engine light is on and I am going to get it checked out tonight.

 

most likely coil/plugs problem like others have suggested.