Hi, Mike Oppland,
Congrats on selling some articles! Finding steady work as a freelancer can be tough. It sounds like you are already registered with Upwork. I haven’t worked through any of the mills myself, but I know they can be good sources of steady work, although they don’t tend to pay much.
I was lucky enough to get a steady gig writing content for a home improvement company through Indeed. It’s a really good source of freelance opportunities, and most of them are ongoing projects. There are some good job listings on the Blogging Pro website.
The other route is to build on the success you’re having selling articles and to try to parlay those bylines into better paying gigs. It’s time consuming but if you pick a niche to specialize in you will eventually gather an impressive body of work and it will be easier to land pitches.
Good luck!