I thought the T hit my range harder. Broadways are a large part of my flatting range from the button facing a UTG raise, so now I have a decent amount of 2pair and straight/straight draw combos. Thought he would back off on the river, and when he didn't I thought it was a pretty easy fold.

It hits your range well enough that he shouldn't just barrel everything, but he still has a significant nut advantage over you at 42.5 combos of 2pair+ vs your 11.

He has:
All ATo/ATs
All A5s
All AK
All QJs
All TT
All KK
All AA
Some 55 (maybe)
Some QJo (probably)

You have:
Some 55 (maybe)
Some QJs
Some TT
Some ATs

The GTO solution has him cbetting only 30% of the time and doing a lot of mixing on the turn. Against which you should be folding KQs something like 85% of the time on the turn. When you get to this river with it, it's pure call.

If I lock his flop strat to cbet range at this size, KQs is still a fold on the turn ~70% of the time. When you get to river it's nearly pure fold.

If I further lock his turn strat to bet TPGK+ at 100% freqs which I think is more likely than the mixed strategy, KQs becomes a fold ~85% of the time with the remainder becoming bluff raises.

Playing around with this, it seems like the only way you should be calling at all on turn is if villain is doing a good job protecting his checking range by putting a large portion of his nutted hands into it.This seems very unlikely at these stakes so you have a ~8% freq bluffraise or fold on the turn.