25-50 Live, Did I play this wrong or just got unlucky?

[FiftyOuts]

BB ($14,500), Hero ($9,500), LP ($130,000)

A few limpers, I limped in MP with 8 [img]/images/graemlins/heart.gif[/img] 8 [img]/images/graemlins/club.gif[/img], LP limps, BB makes it $350. I call and LP calls, everyone else folds

Flops is 7 [img]/images/graemlins/club.gif[/img] 3 [img]/images/graemlins/heart.gif[/img] 4 [img]/images/graemlins/diamond.gif[/img] ($1200 pot)

BB bets $500, I have seen BB make an undersize bet with two high cards so I call and LP calls.

Turn 8 [img]/images/graemlins/diamond.gif[/img] ($2700 pot)

BB checks, I bet $1500. LP is a semi-fish at the table. I have seen him call down a $4000 bet on the river with a set while there is 4 to a flush on board. LP calls. BB raises, makes it a total of $6000.

BB is typically tight. He is not going to make a bluff in this situation. After giving it much thought, I was pretty confident that he had a set which was obviously lower than mine. He wouldn't have raised to $350 with a 5 and 6 preflop. I place LP on a pair with a straight draw. There is an outside possibility that he had a straight but unlikely because he plays his hand pretty straight forward. In this situation I was either calling or raising all in. I decided that if LP was on a inside straight draw that I would want him to call because he didn't have the odds to. I decided to call the $6000 and hope that he doesn't make a straight. LP calls also.

River 6 [img]/images/graemlins/club.gif[/img] ($20,700 pot)

BB goes all in for about $5000 more. I didn't like the river but that pots was huge at this point and I only had $3000 left so I called. LP position calls also. He flips over 2 [img]/images/graemlins/diamond.gif[/img] 5 [img]/images/graemlins/diamond.gif[/img] for the straight.

BB later confirmed to me the he had a set of 7s.

Please critique my turn play? Should I have went all in or was it a good call and just got unlucky on the river?