... Really nervous about someone cleaning the sensor and for the dust to come right back... I heard zooms are notorious for bringing dust in...
Well... I suggest you get over it because it's something every digital photographer deals with on a regular basis. Either have the sensor cleaned professionally or learn to do it yourself because it's going to need to be done and, most likely, repeated on an occasional basis. It's just the way it is. It's certainly nothing to worry about... I mean, it's not rocket surgery or anything.
As for zooms pulling in more schmutz, the old push/pull zooms were known to move air in and out of the lens body but that's not so much the case anymore and certainly not a reason to avoid using zoom lenses; much more dirt and crud enters your camera body when you swap lenses.
Getting your sensor cleaned is, simply put, "one of those things" and yours needs a cleaning. Badly.
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