Wrath/Sunfire + Starsurge in one Macro

I´m having a problem with a macro.
What I want is, that it casts Wrath/Sunfire and every 8 seconds Starsurge.

Currently I have tried this two:
/castsequence Wrath
/castsequence reset=8 Starsurge

/castsequence Starfire
/castsequence reset=8 Starsurge

but the problem is, that it fires off Starsurge after every Wrath/Starfire cast.

Any help would be greatly appreciated =)

Been using this and loving it

/cast [noform] !Moonkin Form
/targetenemy [noharm,dead]
/castsequence reset=8/target Moonfire,Sunfire,Null
/castsequence [modifier:alt] Wrath; Starfire
/castsequence reset=10 Starsurge
/castsequence Celestial Alignment