Questions about Fresh Corn and Sugar Mash

[D4M4G3D_G00D5]

I bought 60 ears of fresh bi-color ohio sweet corn for $20. So I shucked and cut the corn off of 48 ears of corn, rest got saved for dinner. I used a food processor to blend the corn up, no added water (liquefied well without any water). Took the corn cobs and boiled them for an hour and used that water to mix with the corn. Put everything in an 8 gallon pot, cooked the corn with the corn water plus added water to get 4 gallons total. Once I reached temperature I shut off the burner and proceeded to let it cool down. Pitched alpha amylase at temp., stirred and kept at 140 F for 3 hours. Put 2 gallons of cool water, aerated and pitched DADY at 95 F. Mixed in 6 lbs. cane sugar and put everything in a barrel. Sealed lid , put S style airlock in and insulated for higher fermentation temperature.

So after 48 hours it stopped bubbling, has a thick cap, but tastes super sour... no sweetness left.

1. Is that normal to finish so quick?
2. I didn't expect it to finish so fast (never
done a corn shine), will it be ok to sit for a
week?
3. Any advice for future runs?