This deep I like your line. I don't expect any standard reg (assuming they are that) to be betting the turn with worse or to be bluffing for pot. Without any further reads I'd be folding the turn this deep, most likely at 100bb too.

I would not class this as super nitty given stack sizes and turn sizing.

I like the disciplined fold you made to, a nice read of the situation imo.

Here's how see it,
If my opponent is at all competent they can assume I have no AA/KK here after flatting. That usually caps me to something like 99-QQ and the odd AKs type of thing, whereas they remain uncapped.

Since they bet really hard they're either out and out trying to get me to fold by being so aggressive, or they have me beat. For stacks this deep I can quietly lay my QQ to rest this time and obviously take a nice note about villain's line.

Hopefully they'll do it again soon with the nuts and I can feel like Mr Smug for not paying them off last time.

Looks completely fine.

It's tough to call the turn even if the guy makes it a regular turn sizing. Remember that he is 3betting vs UTG open so he will have KK+ with a high frequency. When he bets pot, the decision should be more straightforward, easy turn fold in this case.

I'm happy you all agree with my line Didnt know it was such an easy fold though

I'd play it exactly the same.

You say your cold call should scare him a bit, but it's likely he knows you have QQ JJ AK here a lot, and yet he's still happy to bet pot making it super likely you're up against KK+ hoping that you can't fold an overpair. Coupled with him 3 betting UTG it should really be a simple fold.