I faced this "existential" crisis of a pretty severe nature in my college years. I kept reading stuff about psychology, philosophy, and physics in the hopes of an answer. The first breakthrough against this existential demon came in the form of a course "non-linear dynamics and chaos", the ability of chaotic equations to exhibit life and nature like behaviour, and understanding that life is chaotic, and so is nature. The second one came when I realized that philosophy and reason itself are handicapped, insufficient, powerless against this existential dilemma. The third one came while reading Carl Jung and his work, the fact that consciousness is a very small produce of the biological system that is human body. Fourth when I read Nietzsche's "On Truth and Untruth", which again showed how our speech has taken the form of animal's claws, we fight, threaten etc mostly by what we say, that's like a higher level of abstraction over the physical equivalent. Then there was Tolstoy, who pointed out that its logical that we humans, if we really want to stay true to ourselves, need a god, or something higher than ourselves to believe in, because logically, if you are going to die, there is no reason to live, yet every human and animal does. Then there was "Black Swan" by Taleb, which drilled the idea into my head that we humans don't know even a tenth as much as we think we do. And then there was programming, actually building systems that exist outside of you and do something.
Over the years, I developed the worldview that as human body is formed by numerous of organisms working together, and how futile would it be for a "red blood cell", in all its consciousness, to ask "what is my purpose ?", the same way its futile for human to ask about his/her place in the universe. I started trying to live more like animals do (or rather, how a human animal would live if it only had nature imposing rules on it), copying nature for decision-making, and general wisdom (it even helps me with my work). We humans are basically nature forming a greater system , the human society, which then again competes with many other greater systems formed by other organisms, and till now, has been doing pretty well.
I also have given up trying to control my conscious thought and efforts too much. I trust the biological system that this consciousness came out of to provide me with a better judgement than I can come up with consciously.
Its been around 2.5 years since i cleared up the existential crisis in my head, and my growth since then has even astounded me. I have become better, much better in all spheres of life, and I can't remember a time I was more happier than these 2.5 years