Last nights bad beat

[ytock]

Picture the scene, i was playing a home game with four others,
NL Holdem, with £5 stacks with unlimited £5 rebuys.
Its the last hand, 3 left. I'd cashed in about £5 worth so what i was playing with was profit basically. To my right the chip leader (£20) and dealer for the last hand, to my left the short stack (£5) and big blind and i had about £15 and was the small blind.
i was holding 7h7d
i raise to £5 everyone calls, short stack is now all in
flop comes 7c 2h 5d

i bet £3, dealer calls

turn is 9h
i bet £2 (this is where i played this poorly, should of gone all in?)
call

River is Ah
i push all in (£5), dealer calls

i reveal a set of 7's
he turns over Qh 3h
An Ace high flush
and i walk away even for the night

where did i go wrong and how would u guys have played this?

Id been playing Tight and very aggressive all night as well btw
Dealer had been playing very loose and was pretty much calling all bets when on the button