Can someone please explain to me why lust after results will cancel out your magical workings?
Because it draws the energy away from the magick and into your emotional state in a feedback loop.
If you want something desperately, your magick will work…to make you continue wanting it. You are essentially using your magick on yourself.
This is mitigated a bit by using a spirit as it acts as an intermediary, but your desperation still draws energy away, and the spirit has to work that much harder to overcome it, and thus it will take a lot longer.
Remember, you are a god and your thoughts and emotions carry a lot of power.