I kind of recall playing that map - and it is in my list with a completion score. I remember that I needed a few restarts. But it is indeed do-able. Not sure I want to struggle through it right now just to give you some hints, though. Sorry. Good luck anyway.
You probably *don't* want to struggle through it, because struggle is what it is. My last attempt I decided to abandon the space near the white emitter and defend the one block gap, but all that did was give me an extra minute or three before I was bum-rushed by armored/high-health drones, which of course demolished the level 1 blasters, let in creeper, and generally ruined that attempt.
I cannot downvote this map hard enough.