I really like my job - work on innovative product lines with a small close knit team. I got here by just working on ideas/probelms that interested me and selling that company to the current one.
Go do something you like. Also go to a therapist.
Most jobs are pointless in the global scheme of things.
First, I disagree you should measure mans life on global scale, and secondly I disagree jobs are pointless.
The meaning to many jobs comes from the impact to the community, the people around the employee - "stakeholder value" is the term someone would use. Nurse, cleaner, garbage car driver, teacher, doctor, airplane pilot - all have impactful jobs that create a physical and psychological imprint on the world.
If you seek global impact - I don't think a single human being can have much of that - and seeking global scale effects reeks of megalomania.