Worst River of my life

[bomblade]

I have 77 in the cutoff. 3 limpers before me. SB completes and BB raises. 20-40 decent game. Good action. Flop comes 974, all hearts. BB bets and all call, I raise and BB reraises and knocks out all the others. We're heads up on the turn, which pairs the 9's. BB bets out.
I'm in the 4 seat and he's in the 8. We've had many battles throughout the marathon session, and we're both staring at each other trying to pick up a read. I am fairly certain he has AA, with the A of hearts. At this point though, he could have any overpair and the result would be the same.
I raise the turn, and he takes a minute or two and calls.
The river is a 3rd nine. So the board is 99974, three hearts and my had crushed.
If this pot is checked to you, what do you do?