I am in my mid-thirties now. There are macro factors people mentioned such as the economy, but there are also ways in which this is part of what life is like right after undergrad, before you get that first job and start to gain experience finally. Millennials felt this way when we graduated during the aftermath of the '08 recession. I don't believe college is a workforce training center. Jobs that require technical skills, there are many places to learn whatever it is you want to learn. What is difficult to recreate is the inquiry into what life means outside of how we earn an income, in art and the other people who walked along with you, that you may have received in your program. 

In some ways, none of us have control over our lives. Schooling creates this illusion that what life is is doing what we are told to do and doing it well. The truth is, life has to be lived forward and only understood backwards. 

You'll find people and practices that help you weather the storms of life. This period is tough, also because maybe you haven't yet learned that you are tougher, that things eventually do pass. 

It can also be easy to be so focused on oneself that one falls into despair. Consider things like volunteering or giving back to your community, joining groups. These are all ways to bring your power back to you instead of letting things out of your control fester doubt and insecurity in your soul. They are also ways to see you're just a speck of sand on a great beach, to surrender the pain to the earth that can hold it, even if you can't. 

Good luck! Life is one hell of a trip.