summary: if you dont feel like reading the below stuff, i am basically asking if my goal is to increase set five by 5 lb. a week, when should i increase set 1 through 4 weight?

for my 5x5 split i have, if i can complete my last set of an exercise with 5 reps, i will increase set five by 5 lb. the following workout. My question is, when should i increase the previous set's weight (set 1-4)? When i can't complete all 5 reps of the last set, should i increase set 1-4 by 5 lb.? should i then leave set 5 alone until i think i can increase it by 5 lb.? should i then keep the added 5 lb. to sets 1-4 once i can get that extra 5 lb tacked onto set 5, or should i resort back to my previous weight for sets 1-4?
am i just overthinking this? what would you guys do to continually increase how much you can lift by ~5 lb a week if doing 5x5?