Game is Ignition Casino anonymous zone so no reads

Blinds: $0.10/$0.25 (6 Players)
BN: $42.21
SB: $45.49
BB: $26.59 (Hero)

Preflop
Hero is BB with 22
3 folds, BN raises to $0.75, SB calls, Hero calls

Flop
($1.30) 5 2 4 Rainbow
SB checks, Hero donks $1.37, BN calls, SB raises $7.73, BN folds, Hero calls

Turn
($18.13) 5 2 4 10
SB shoves, Hero folds

Is my donk bet on the flop bad? I've seen some good players do this once in a while. I probably should've bet 2/3 pot instead.

Also, on the turn should I be calling here? Am I being too nitty?
He called from the SB so I expect him to have alot of pocket 5's and 4's, maybe a straight already