How do I deal with feeling uneasy about how well I can make people want things?

You can read what a market wants with a precision that unnerves you, because you have noticed you can do more than find desire, you can create it. That unease is not a flaw in you. It is your conscience doing its job, and it is worth listening to rather than arguing away. The skill itself is neutral. Understanding what people want deeply enough to move them can sell them something empty, or it can connect them with something that genuinely helps. The same insight does both. What decides which one is you, and the standard you hold for what you are willing to point it at. Power over wanting is only as clean as the thing you are selling. So make your conscience a working part of the job, not a voice you silence. Before your next campaign, ask one plain question: if this person fully understood what I understand, would they still be glad they bought it? Only aim your skill at the things that pass. You cannot unlearn what you know about people. You can decide to use it on things you would stand behind.