Hi waffle, this is a tough hand. I don't think you played it terribly. One thing I'll say though is that with middle pocket pairs I definitely prefer 3-betting pre-flop vs calling and check-raising the flop. Compare a hand like 88 to a hand like KJ. With KJ, we're likely to have a better idea of where our hand stands after we see the board cards. This isn't always the case but it often is. E.g. if the flop comes Q69, we can probably give up on the turn or even after he 3-bets. However, if the flop comes K69, we can be very confident about our hand. Whereas with 88, we don't know where we stand with either of these flops.

Essentially, with KJ our hand will often be weak enough in relation to the board that we can muck it easily. This will rarely be the case for a hand like 88. As more cards come out, our hand is likely to look dicier and dicier, but it will still be strong enough that we don't want to fold. So with mid PPs I like to 3-bet pre-flop and lead the flop, and do my best to get the hand over with as quickly as possible. It is very rare that a turn or river card will help your pocket 8s - it is more likely to help your opponents big cards. So I say get your money in while you're ahead and try to win without a showdown.

With KJ I like the calling and check-raising the flop line better. It is more likely that the board cards will improve your hand, and you won't mind seeing turn and river cards as much.

Not sure if this is right, but it's something I've been thinking about lately.