I think it's the overwhelming amount of things we need to do everyday. Combined with the stress of not making enough money. Also that too many hobbies are selling out and raising prices. You just want to stop worring and not have to make decisions. Just a grab bag of stress and depression.
My whole life is a could have been. Largely based on income.
I'm doing better now, but only cause I've set stubborn boundaries of what I'm willing to deal with, and don't budge ftmp. It helps that I have chosen not to have children. I can't even imagine.
I've come to understand that I don't personally need much to express myself in a manner that is productive. It's soul food. I do it when I can and only because I want to, or need to. I don't really care for all the other stuff surrounding my hobbies, I just like doing.
Maybe it's perspective or a shifting of expectations, or maybe I just know that to see another day, my way, I'll need to do the work. This system is broken, and I'm doing my best. I try not to feel down on myself about that.
Now health concerns are getting in my way of certain things, and the Healthcare system is a joke to the point where seeing a doctor is like pulling teeth, and I just have to work around my ailments, telling myself decay is just apart of life. (:
It's even worse for Marxists, as you have to find time to read theory all the while trying to debunk the newest neoliberal propaganda, which means reading no less than 10-15 articles a day.
There's a term called brandolinis law that applies more for US propo than it does for anything else I can think of: in takes 10x more effort to refute bullshit than it takes to create it.