Is 20% of a paycheck lost to taxes in the range of "normal"? ELI5.

I don't have a huge long work history to compare to, in fact this full time job I started in February is my first serious employment.

Was waiting for my paycheck anxiously since I know I had a shitton of overtime this pay period, when it arrived I found it had a full 20% given straight to taxes. I did the math and my last paycheck had 15% and my first in February had .05% (which is why I'm asking)

Like I said, I am inexperience in the ways of money and would appreciate a nice eli5 as to why I'm only getting paid for essentially half of my overtime in this 112 hr period...