Am I just gunshy? or do I have cause for concern?

PokerStars: Hold'em No Limit ($0.10/$0.25
Seat 1: FNBLAZED ($19.80 in chips)
Seat 2: Falbrav ($6 in chips)
Seat 3: poker512 ($24.25 in chips)
Seat 4: chavez669 ($8.35 in chips)
Seat 5: schmichaels ($28.75 in chips)
Seat 6: SillyString ($22.05 in chips)
Seat 7: Amb1s1225 ($19 in chips)
Seat 8: CAVPilot ($25.15 in chips)
Seat 9: Mardagg ($22.75 in chips)
CAVPilot is the button
Mardagg: posts small blind $0.10
FNBLAZED: posts big blind $0.25
*** HOLE CARDS ***
Dealt to SillyString K K
Falbrav: folds
poker512: folds
chavez669: calls $0.25
schmichaels: folds
SillyString: raises $0.50 to $0.75
Amb1s1225: folds
CAVPilot: calls $0.75
Mardagg: folds
FNBLAZED: calls $0.50
chavez669: folds
*** FLOP *** T 5 6
FNBLAZED: checks
SillyString: bets $2.50
CAVPilot: calls $2.50
FNBLAZED: folds
*** TURN *** 7
SillyString: bets $5
CAVPilot: calls $5
*** RIVER *** J
SillyString: checks
CAVPilot: bets $5
SillyString said, "did you hit your set?"
SillyString: ?

I have to call this, but do you think I am beat most of the time? No real read on opponent. What if he pushes all-in, then what do I do?
With all the connectors out there, I had a serious worry about 2 pair.

Bet the river, if you get reraised hard then maybe you can consider folding, but if you check you're not getting any information and of course he's going to stab at the pot with a 3 flush/3 straight on the board when you check to a scare card...

hes got 7/8