Probably fold now.
By the way, I think the turn sizing was really bad. If I'm going to bet the turn hoping to get called by worse here (and I am), it has to be a bet that worse will be willing to call. In my experience at LLSNL, when the flop comes out all one suit, most people play REALLY weak-tight. So the problem on the flop and turn is, even though there's not really a reason to think you don't have the best hand, getting worse to call you is actually pretty tough.
That's why I hate betting $200 on the turn. I want to bet, to be sure, but when you bet $200 you are basically letting your opponent fold everything that you beat AND you're making it clear that you're pricing him out of calling with the A
. I would have bet less, as others said earlier in the thread.
I think it's very hard to imagine that the small river bet induced a raise from something we beat. Probably we're up against a slowplayed flopped flush.