Relax, take a deep breath. Uneven floors are not an uncommon problem in cabinet installation.
My floors were uneven, I think by only a quarter inch, though, on a 78" cab run. I used Ikea cabs. The contractor made a level frame, eventually hidden by the toe kick, and placed the boxes on top of that. So, the tops were level, and the toe kick was cut to adjust for the uneveness of the floors. The more traditional approach w/ Ikea cabs is to adjust the adjustable legs, but my contractor did not like the legs and preferred to place the boxes on a framed base.
Be careful to allow appropriate height for a dishwasher or range in the run, if the plan calls for that.
Q