Do I have c-bet OTT?

First i would 3bet this pre flop. I mean this should be your standard 3bet vs CO in this spot. Flop call is ok, but turn play is fold or just complete 1,5 and fold to river shove. You need to check hand histories against this guy, cause i think he always does double raise on "nuts".

On turn, you need to ask yourself why would he check-raise Q,flush draw or any bluffs?

You really should 3bet that hand agaisnt the CO.
Villains check raising and shoving on the next street, usually means trouble.

3b pre.
would fold to a raise on the turn.
You're behind, could potentially be vs some combo draw / 9x

What range do you put him on that you beat?

Preflop I'd 3bet too.
I think the hand is played ok postflop.
The problem with these stakes is that villains don't bluff-raise turn enough and act accordingly OTR.
So, I believe calling turn is ok in position, but the donk shove I would fold most of the times. Take into account that it was a mwp.

Preflop mix is fine actually with AQo if you have a reasonably wide flatting strategy on the button, good to have some high Ax hands in the flat range
Post is fine I'd just fold the river random Qx doesn't make sense anymore you block nutfd
Turn check back seems reasonable also I'd say, check back then call when one of them bets, bet really big when it get checked through to rep our own draws

~hope to see you guys in chat tonight, we'll play Stars Reg tables live!
https://forums.pokerstrategy.com/forum/thread.php?postid=3033687#post3033687

To me check raise on the turn looks super strong. And even stronger 3 way. I would fold on the turn raise.