I was dealt a flush K high and worried about the ace a bit. Also a straight flush was possible. Should I have been more careful

0.25/0.5$ NL, 50$ buy in, 10 players

Dealt to Borax in LP (K3)
5 callers of BB 0.5$
Borax calls 0.5$
FLOP (JT9)
one fold
Player X check
Player Y check
Player Z bets 2$
Borax raises to 4$
Player BB calls 4$
X calls 4$
Y calls 4$
Z raise to 8$
Borax raises to 16$
BB calls for 10.5$ and is all in
X folds
Y folds
Z raises to 25.5$ and is all in
Borax calls 9.5$
TURN (2)
RIVER (4)
Z shows (Q8) a straight, Q high
Borax shows (K3) a flush K high
BB shows (A6) high card Ace
Borax wins pot