Commerce 40 - Narrow Range River Spot

TAG regular opens in late middle position and I 3bet AKo next in. Folded back around to him and he 4bets (which surprises me because I have never seen him 4bet out of position HU before the flop). HU to the flop.

Flop AQ3tt. He bets, I call.

Turn Jr. He bets, I call.

River 9r. He checks, I bet, he raises. I puke, question whether I should have bet the river at all, and very reluctantly call.