Need help. I seriously need professional help.

actually, i have the answer right here for you
and...i have it from real life experience

I musta been 16 at the time, 17 tops and my main means of getting around was a two stroke 80CC dirtbike
for whatever reason I decided to do a tune up
new plug, new wire, and why not...new points
in order to get to the points I had to pull the fly wheel off
so I did, and wouldn't you know it, I lost the index key

no problem, ill just eyeball it
got it back on just fine

gave it one good kick and she fired right up
so I grabbed my helmet (it was getting close to beer o'clock) and hopped on
I gave her a big twist of the throttle, kicked her in gear, let out the clutch....and over the handle bars I went
apparently, I got the flywheel off just far enough that the timing was so far advance that then engine was now running in reverse

so, all you need to do is advance the timing on your mower far enough to run her in reverse, and all is well