[10NL] HU- All in first hand?

Hero-Q9os (10.00)
Villian-? (10.00)

I raise 3x and he 3bets me.

FLOP- 4/7/Q rainbow

Villain bets 1/2 pot, Hero calls

TURN- 6 of clubs putting a FD out there.

Villain bets 1/2 pot, Hero calls.

RIVER- J of diamonds

Villain bets 1/2 pot and is all in, Hero ?

I would think after putting in so much money flop/turn you hafta call the river. Probly shouldn't be flatting 3b's vs unknowns with Q9o, guess that's how you got into this spot to begin with.

Yea, I guess I got caught up in thinking its the first hand and I need to set a precedent of not being pushed around sort of thing but in the future I'll tighten up my 3-bet calling range. He had AA and then quit after I doubled him up. Hit and runs tilts me