first taste of high stakes, how is my play?

[ukdentisto32]

OK, so im not a high stakes player by any means. i play mostly higher heads up SNG and 9 person SNG. but recently i sat in with the full buyin in a 50-100 game on tilt (prob a bad decision right away). so heres the hand (sorry no converter, workin on it)

Frodooo - $3600
Lars Luzak - $10000
hero - $12000

ive been playin pretty tight aggressive. i just took down a good size pot against lars and we have been going back and forth but have seen few showdowns. i open from the button to 300 with Jh8h, lars reraise to 1000. frodooo folds and i make the call (yes not a great call), flop is KhTs2s. he checks i check, turn is a 6h. i bet 1400 he calls. river is a 7c. he checks, i bet 4000..

good, bad, terrible?