loose 2/5 game with most people deep with some players 1k+
My Hero starting stack about 350

UTG opens to 15 2/5 I flat in the CO with AJss, SB tight nitty player who folded 2 pair to 400 shove earlier flats, flop is AQ8r, I bet 25 into 75, SB flats, turn AQ8Tcc, I bet 55 and get CRed by SB to 175 (pot is 180).... I fold (I'm really foggy and brain damaged by lung disease)
The first time vs a new player isn't this possibly a bluff? anyway what is this player's bluff frequency in this spot....

the player seemed to possibly be bluffing but he laid out his chips in a big pile and the check raise is exactly pot (I have really thick glasses) and may think he can get me to fold since my line is weak. some percentage of the time I may have the best hand on the flop even 5 ways so I bet to try to win the pot. somehow though I don't think the SB is calling even 2nd pair or Ax except AQ 5 ways with other loose players behind maybe he had AQ or 88, since there are no draws maybe he might just call the flop with a set or 2 pair

Against an older experienced good player I think I should check turn and consider calling river.

Grunch.

Good fold. Against the described player, you basically never have the best hand here. He's almost always got two pair+, possibly even the nuts given you bet the flop so small.

I know AJs can look like a sexy hand, especially if you've been card dead. But this is a fold pre-flop. What hands do you think V is open raising UTG? The answer is likely hands that crush you or that won't pay you off when you hit.

When we are beat we are beat.

Can't stack off "just in case".

We should aim to play better cards in better position.

I don't like your sizing at all.

1/3rd pot is way too small.

Bet 2/3 pot at least.

It's definitely possible villian is making a move because your bet is so weak.

Whether he is or not is a different question but bet bigger in future.