As yet, they haven't developed a robot to complete FRAs or carry out fire safety work. Only humans can do this and as such, we all have an inherent design fault, ion that we sometimes make mistakes.
It's my view that making a mistake or in this case, an omission, is absolutely fine as long as you learn from it, grow and move on. At a time when I am coming to terms with the lies, spin and downright wilful negligence and fraud being demonstrated by some in our industry during the Grenfell Inquiry, if you don't mind me saying so, throwing your hands in the air and packing it all in over what is a small accidental oversight is somewhat excessive.
As a regular on here I have noted your professional motivation to do the right thing. I have shared your pain when observing your efforts at one particular project where huge difficulties challenged you but you kept on going.
I am sure you will never miss checking a kitchen ceiling again given the same opportunity, so recognising a mistake and learning is the key. So in the words of Winston Churchill - my advice is to KBO