I agree with your line, but larger bet sizes could have been used to prevent the turn overbet. A turn overbet could fold out the weaker hands, like 7x, 5x, and FD that you want in the pot against you. If you can keep weaker hands in your opponent's range when the big money goes in, the better it is for you. That being said, one of the worst cards came off on the river and you got unlucky, but you were most likely ahead on the turn when the money went in. According to the Fundamental Theorem of Poker, you gained here, even if you lost the hand.
A more fundamental point here is that this hand IS NOT a nuts or nothing situation when the money goes in on the turn. There is no action from your opponent to believe he has the nuts, partially due to you taking the initiative and not providing him a chance to tip his hand. If this was truly a nuts or nothing hand, you are thoroughly trapped with your KK based on your betting action when he has the nuts, and he will fold all non-nuts. Your range is not polarized into nuts or nothing, either. Also, note that the nuts on the turn (a set of queens) is up against two flush draws, gutshot straight draws (A3, A4, 48, 89), and belly buster straight draws (34, 46, 68), all of which are drawing to beat the current nuts (some of these flush draws can improve simultaneously with the set of queens going full).
Be careful assuming nuts or nothing too early in a hand. This assumption could cause you to call too tightly and make many folding mistakes with hands like top pair, low two pair, etc. I would recommend you review your database and try to determine if you have more hands where you have made this assumption. You may find that you are making mistakes you were unaware of with this assumption.