With 7 players left behind ATo should be folded, and even AJo is close. As played you could check the flop for pot control, since you hand is somewhat in between, but C-betting is also ok. However when you get raised, your hand is clearly only a call and then evaluate later, if he continue to fire big bets. 3-betting and then calling off his jam is a massive overplay.
He only need AQ or AK to have you in really bad shape, and he can also have JJ, 77 or AJ, which has you drawing nearly dead. Yes from time to time he might also have a draw, but even then he has around 40% equity, and as the outcome illustrate, he will sometimes realise that equity.
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