Two Plus Two Newer Archives - Live hand, tricky river.

Sorry if I am formatting this wrong, but this hand was played live so this is all by memory. I was playing in a soft game 10/20 nl game that I try to hit up everytime I am in town. Stack sizes are pretty close, but could be off a bit. Game is 5 handed, with one rock, one super laggy kid that won 8k playing blackjack so decided to sit at a NL game that nite, a super degen that is always stuck every time I am in town and always plays like super laggy unless he having to short stack, another regular who was playing super tight. Pot was almost always straddled, and I have a pretty tight image and was getting cold cards all nite. Here is the hand that gave me problems.
I am on the button with 4[img]/images/graemlins/spade.gif[/img] 4[img]/images/graemlins/heart.gif[/img], and the pot was actually not straddled. I raise it up to 60 with about 2700 in my stack, laggy kid called in the sb with about 1500 left in his stack, super degen calls with about 2k.
Flop comes Q [img]/images/graemlins/spade.gif[/img] 4 [img]/images/graemlins/diamond.gif[/img] A [img]/images/graemlins/spade.gif[/img]
SB checks, BB bets 150, I called here (I still think calling here was a bad play, but the SB seemed to love calling into these kinds of pots with [censored] hands, but I digress)
SB calls
Turn brings K [img]/images/graemlins/diamond.gif[/img]
SB checks, BB bets 450, I call hoping the SB doesnt shove J10, SB folds.
River brings K [img]/images/graemlins/spade.gif[/img]
BB insta bets around 900

What's my line here? Is this always an auto shove? Does the flush pretty much HAVE to call a shove here?

BB is the super laggy degen who was tilting pretty bad, so J10, spades, Kx are all in his range. He always overbets AK pre-flop so I took that out of my range. My I think my flop call was pretty [censored] with the flush draw out there, so please dont just comment on that.