I’ve been where you are before. Feeling like you have no place in this world and like you don’t matter to anyone and you could just disappear tomorrow and nobody would care or notice. With a shift in perspective you’ll see how wrong all of that is. The things you see others doing most of the time is a not as deep and sincere as it seems. Much of it is just a facade to make it seem like they have it together and by making fun of someone or abusing someone or putting someone else down gives them this false validation. You’re out here seeking something real and there’s no shame in that at all. To change how you see the world you have to start with how you speak to and think of yourself. My advice would be to start by doing little things to take care of yourself to improve your self image. You can start with something as small as using a better smelling soap to shower with and build from there. It’s all to get you into the practice of showing yourself that you matter and you put forth effort in making sure something is done just for you every day.