I learned to accept the world the way it is after I spent some time studying art. Many artists were effective self-promoters, but it is not seen as a bad thing because they were subtle and not pushy about it. When most people think of self-promotion, they think of a pushy, sleazy used-car salesman. That's a very narrow view of the world.
There can be beauty and subtlety in image-making, diplomacy, and other "soft" skills just as there can be beauty and subtlety in a well-written piece of code or in a theorem proof.
Learn to perceive the world from an impartial point of view of an outside observer (or from a point of view of someone wielding power), not from a narrow resentful point of view of someone trying to spread a hateful message to agitate others for whatever vengeful cause. Consider all possibilities. Unlike what the Tolkien's tale says, it is okay to like power; what's not okay is to misuse for a hateful cause. One can't know what misuse is without diligent observation of others. One can't become alpha by acting like a beta.
Recognize that even your claim that you dislike self-promotion is a mere attempt to promote yourself to others who (you hope) are just like yourself. Think again about whether people like yourself are a worthwhile bunch to be around. Strive to be around people better than yourself, not just around ones who are your equals. Read Nietzsche.