I would reflect first on why you have chosen to embrace absolute and nihilistic egotism and selfishness. This is ultimately a choice you’ve made. It’s like asking “why don’t I just stay at home masturbating all day?” You can do that and no-one will stop you, but it may not be a very rewarding life, and eventually you will regret such a shallow and unnatural mode of existence. Something inside you must crave meaning, even if you’re trying to repress it. The escape from egotism isn’t always easy, but it is an essential part of growing up. Embrace the desire for something beyond your self.
Once you understand the innate baseness and falsehood of pure egotism, you will probably also come to appreciate that the lives of other people, in general, have the same worth and validity as your own. Then the absurdity and cruelty of capitalism will be apparent, even if you don’t necessarily feel you suffer from it personally (which I would assume is the case, given the nature of your question).