"How do you build a small fortune in the arts?"
"You start with a large fortune."
The arts are a horrible business. For profit. Non-profit. It doesn't matter. Any business where costs can sky rocket and revenue is terribly inconsistent is not a business a smart person would get into.
So it's important to remember that there are much, much, easier ways to make a good living. Start a landscaping company. Start a company that hauls and recycles junk. People have lawns. They have junk that needs to be moved. Both of those are viable business.
But if you decide to stay in the arts, then try and remember this:
The only ones who make it in this game long term are the ones who love it so much that they can't let it go AND they are smart enough to make good decisions. That mix of passion AND clear thinking is rare, but it's the only way to survive.
Otherwise, stick to dog walking.