Requested WoW macro

I want a macro that would utilize healing on a Destruction Warlock while using the Grimoire of Sacrifice talent, sacrificing Voidwalker for its Shadow Bulwark. I tried using a macro in this format:

#showtooltip Life Drain
/cast [nomod] Life Drain
/cast [mod:alt] Shadow Bulwark
/cast [mod:alt] Ember Tap
/cast [mod:alt] Healthstone

I know that Shadow Bulwark isn’t necessary for a bigger heal but it gives cushion on percentage of health when it returns back to normal after 20secs.

The problem that I have is that, after casting Shadow Bulwark, Ember Tap doesn’t go off even if I have one ready to go. The only bypass I can think of is making a sequence out of it but I don’t want to press the button more than once (hurray for macros!!)

If the community would be so kind as to help me find a remedy for this situation, thank you!