I feel like a turn check is too weak and asking the other guy to take the pot away, and a weak turn bet just might as well be a check. But a strong bet gets me into crap like this. What do you do?

Party Poker Pot-Limit Hold'em, $ .5BB (10 handed)

Hero ($49.5)
MP2 ($35.65)
MP3 ($72.41)
CO ($58.8)
Button ($49)
SB ($48.55)
BB ($8.05)
UTG ($45.85)
UTG+1 ($75.75)
UTG+2 ($33.55)

Preflop: Hero is MP1 with , . SB posts a blind of $0.25.
2 folds, UTG+2 calls $0.50, Hero raises to $2.25, 2 folds, CO calls $2.25, 2 folds, BB calls $1.75, UTG+2 folds.

Flop: ($7.50) , , (3 players)
BB checks, Hero bets $7, CO calls $7, BB folds.

Turn: ($21.50) (2 players)
Hero bets $20.45, CO raises to $40.9, Hero folds.

Final Pot: $82.85

Results in white below:
No showdown. CO wins $82.85.

A turn check is not too weak. He called your flop bet so he what does he have?

Most likely, AQ or a flush draw
Or hands that have you beat already like TT or 55.