it depends on your play style , i personally would do this .

You have 17 skill points correct ?
important skills at your level i would go .

Mind Wrack-3
Flames of insanity-5
Amplify Pain-5
Neural shock-3
Lurch-1

*keep in mind that i have not tested this build at lvl 15-20 pvp , i based those numbers from end game pvp on what may be useful for you.

your combo if using that build should be :

Flames > Lurch > pain > neural> wrack > repeat.

* Tips - play smart , time your lurches well.