AA in a huge multiway pot

[setzf]

Game is live, 6-12, 9 handed, with a typical mixture of small stakes opponnents. Here is SB with A [img]/images/graemlins/diamond.gif[/img]A [img]/images/graemlins/heart.gif[/img].

Pre-Flop: 1 fold, UTG+1 calls, UTG+2 calls, 1 fold, MP2 calls, MP3 raises, Button calls, Hero 3-bets, BB calls, 5 calls.

Flop (21 SB): 8 [img]/images/graemlins/spade.gif[/img]7 [img]/images/graemlins/spade.gif[/img]5 [img]/images/graemlins/club.gif[/img]
Hero bets, BB raises, 4 cold-calls, Hero calls.

Turn (17.5 BB): Q [img]/images/graemlins/club.gif[/img]
Hero bets, BB raises, 2 folds, 2 cold-calls, Hero calls.

River (25.5 BB): Q [img]/images/graemlins/spade.gif[/img]
Hero checks, BB bets, MP3 calls, Button raises, hero folds.

I hated how I played the hand but felt stuck between a rock and a hard place. Any advice is appreciated.