I think you are mixing some things together. For starters, you should distinguish between a "life's purpose" that you set for yourself, and one that you assume

I think you are mixing some things together. For starters, you should distinguish between a "life's purpose" that you set for yourself, and one that you assume for other people. You can only decide for yourself, not for other people. You may wish other people had specific values, and try to enforce them with violence, but you can not decide for them. Next, you should distinguish between a goal or purpose and the means to achieve it. If you goal is to achieve world peace, it doesn't imply that you know about a sure way to achieve it, and you don't have a guarantee that the steps you take are the right ones. That doesn't imply that it is useless to try, though. Ultimately, what I find sad is that apparently you need some external validation for your existence. You can not stand on your own. It is as if you were missing a leg - that would be sad, no? I am not sure how to describe it better. I think if you are feeling emptiness and can't appreciate things, very likely the reason is much more basic than "a general lack of meaning in life". Personally I think it is much more likely that the root cause are emotional problems in your life, loneliness, not getting along with family and friends and stuff like that. Good luck in finding your way!