Feeling lost with a full house

[James282]

I have never seen the opponent in this hand get out of line, his numbers are 15/5.5 for 500 hands. In this hand, he has 2200 and I have him covered.

I have A5o in the BB, he open limps UTG+1 and it's folded to me, I check.

Flop is A65 2 hearts. I check, he bets 55 or so and I call.

Turn is an offsuit 5. I check, he bets 100 and I call.

River is an offsuit 8. I check, he bets 300, I cr to 700, he goes all in without thinking and I folded.

This hand felt insanely weird. I had a good read he wanted to bet the river but also felt confident about the fold. This was like the most muddled hand I've ever played at NL and since I've played badly today I figured I'd post this one. I think the CR was kinda bad. I think I either need to bet out or bet call. Ugh.
-James