Final Table 8 players left blinds 1000/2000 no ante.
I'm on the BB with

nursing a a relatively healthy 56k in chips. Every player folds round to the Button who has just won a few pots and is chipleader on about 90k. I have played against him the previous night and with position he likes to get in with virtually ATC (connectors etc) with a limp or sometimes a raise - I have also noticed he over-defends his blinds and thinks everyone is 'AT IT' when they raise when he's in a pot. I feel I have the measure of him and have outplayed him a few times post flop.
He limps OTB into the pot for 2k and the SB folds.
I raise the pot from the BB to 6k and he ponders then calls (not unusual)
Flop comes

I bet 9k and he thinks for a bit and calls
Turn

I bet 12k and again he thinks for a bit and asks me how much i have left, i state "20500".. He toys around for a bit then puts me all in....
Here's my thinking at the time 'OH FUKK' sorry here's my thinking - The limp was weak pre-flop and I have seen him rasising with A 10 upwards no limping - but he will limp with connectors etc so maybe A rag. Possible limp with AA KK but he's not coming over the top with KK surely so Ace rag is more likely IMO. Now if he has limped with A rag and flopped 2pair or FH i'm obviously in bad shape but I have a distinct feeling he's at it here so now i think I have put 30k in the pot I can still play 20k and chuck this hand.. He doesn't look to confident and I cant seem to put him on a hand that beats mine.
I call and his face is a picture of misery till I flip over and show

and he laughs and shows

and people on the table say good call etc... The river brings

and he four flushes me out of the tournament.
I play these things to win but I cant help thinking a really fekked up again at the business end!
Did i do right to play it like i did and was just UL or should i have waited for a better opportunity..
I was afraid of no-one on the table although i respected the players and with hindsight obviously i'm beating myself up.
My question is if you were sat at this table and seen that hand how would you have played it yourself???