I've read this 4 times and I'm still confused.
last session my first set of my new novice PR felt easy. then when I looked again its because i forgot to add 5 lbs. what I did was practically 4 sets and luckily succeeded, with the first at 200lbs and the next 3 at 205 lbs.
i am feeling good that day that's why I finished through it, though as i squeeze a little more lbs, I think what I did will not become an option for I am currently squatting ~1.5x Bw at ~135 lbs
my question is that did i do the correct thing? if not what should I have done?
I've read this 4 times and I'm still confused.
Of course it's not an option. You made a mistake and forgot to add weight so you did your best to try and fix the situation. There is no option in SS to do 4 sets of squats.
You probably should not have done 4 sets. I'd have just done 2 more with the correct weight and carry on as usual next session, by adding another 5lbs.
It's not really a big deal at the moment since you're not at the end of your novice progression.
You're a novice, and you're pretty early in your progression. There's basically nothing you can do that will hurt your gains right now, as long as you're lifting and eating big.
A good quote I heard a while back was something along the lines of "Even the best program followed without desire will be worse than the worst program followed with determination." I think that's probably only true for novices, and maybe intermediates, but it's still a good idea.
Lift with ferocity!