Following some recommendations on @solarpunk I picked up “The Dispossessed” by Ursula Le Guin, and I found it right up my alley. I went through it as fast as I could, unable to put it aside for long. There were a few aspects which I did not need (the Terran connection in particular messed with my suspension of disbelief), but overall I found it a very good start to dive into reading fiction again.