your recipe above. my recipe below
when proofing your yeast, proof it in a small portion of water. if you heat the entire water, the dough will be too warm and will continue to rise even though the outside is down to temp.
try proofing the yeast in a pint, or even a cup of water at 105ºf. add it to the rest of the recipe, with the oil added last, during mixing when the dough is juuuuuust incorporated. i don't know what flour you are using, but i assume you are using AP or bread flour?
with 2% sugar you have a lot of food for the yeast to feed on with the entire mass at yeast activation temps.
some things that will help figure out what is wrong:
what type of yeast did you use
what time period did you want the dough to be ready in?
what type of pizza are you trying to make?
If I did calcs correct this would be (i'm not sure i have the water conversion correct):
1 gallon of water is 8.61lbs. so 1.5 gallons (6 quarts) would be 12.91lbs or roughly 51.x%hyd