You're a Bunch of Factors

$5 sng, 9 man.

Early stages, 7 left.

Blinds 20/40 I have 1410. I pick up AJo in MP, folded to me. I make it 140, BB calls.

Flop: [ad] [td] [7c]. He checks, I throw in a pot bet of 300, trying to appear weak. He calls... hmm.

Turn: [qd]. He checks... flush draw? I bet half pot, 450 ish. He calls... we both have about 400 left and are committed at this stage.

River: [6s]. He shoves. I don't like it... but I have to call.

Rolls [Qs] [6h].

I'm left with 75, out a few hands later.

Turn: . He checks... flush draw? I bet half pot, 450 ish

There's your error.

The board is not straightening and flushing. Your options here are shove or check. Don't bet for value here online, especially if you are committing yourself to a call on the river.

Bet sizing and stack awareness of your opponents is crucial.