That 10 year look back will kill me if I wait the full retirement age. Layoff/early retirement in 2013, took care of a cancer patient in 2014/2015 and went back to work as a contract worker last June. I get a very modest pension but need the fulltime job status like yesterday in order to make this work. This sucks.
As I have already posted: it's not a "10-year look back".
Social Security considers your highest 35 years of taxed earnings (after adjusting for the change in average wages each year). If you don't have 35 years of earnings, zeroes will be substituted for the remaining years.
Waiting until your full retirement age or starting at age 62 (or waiting until age 70) will affect your benefit, but it has nothing to do with a "look back". Every year you wait after age 62 increases your benefit by 8%.
Any payroll income may help you, if the annual amount exceeds your adjusted wage income from earlier years. My earliest jobs were part-time after school, and it didn't take much income later to "bump" them off the calculation.
Your response is a classic example of how incorrect information misleads or even panics people into making bad decisions.
But, I encourage you to not take my word for it, either. There are various online calculators that you can use to predict your Social Security benefit. The SSA has one here:
https://www.ssa.gov/planners/retire/AnypiaApplet.html
It's not very detailed, but it's a place for you to start.