I find the question hard to answer 
How to not tell my whole life and how to share something semi-organized? What things had an impact and which ones didn’t?
Please excuse the randomness that follows
I don’t dare to say I “successfully transitioned”… it’s always an ongoing process. So far it has worked out but I never know about the future.
It was not a straight line for me. At one point I didn’t want to continue developing software for others, and I went for a 3 month travel in Asia. After that I moved to Finland and started recording Processing video tutorials. I was able to do that because I was living with my grandma with almost no expenses. The tutorials eventually brought me opportunities to give workshops and teach in universities. For a long time I tried to experiment every day and post results online.
Initially I did more work for other artists or design studios than for myself. I made money in various ways: teaching for groups or private lessons, workshops, mentoring, work for artists, for design studios, grants, art sales… The works involved sound programming, algorithmic visuals, interaction, Raspberry Pis and Arduinos, visual effects, shaders and live performances among others. The programming languages also were various: Processing, Java, C++, JavaScript, Kotlin, GLSL.
Even if there was much variety, there was a direction: creative uses of technology using Free Open Source Software.
I joined / started two creative coding communities in Berlin: the Sonic Code Sessions and Creative Code Berlin. I’m still part of the second one after more than 10 years. I find it valuable to meet twice per month and see what other people are creating and hear their stories. Paid projects have come sometimes through these communities.
One challenge is sometimes motivation: I can find it hard to be creative while being aware of the challenges life in this planet is facing. Another challenge is thinking that new creations must be better than previous ones, or not allowing myself to play because creations should be worth exhibiting. Perfectionism. And more challenges: addiction to Internet. How often to share online? When? How to avoid getting lost scrolling? I try to avoid anything that is addictive. I could write a long post on all the things I have tried over the years
I think that those having a full time job doing software don’t always have energy for creative coding after work. On the other hand, it can also be hard to enjoy what used to be fun when it becomes a full-time job. This balance is tricky. At times I wished I had a regular part-time job somewhere with not so much thinking, maybe interacting with people, or somewhere where I could read or learn during work. A part-time job can also help.
Health is another thing to pay attention to. Working with the computer can affect health at some point. It’s easy to get lost in the code and forget about our bodies. It’s important to avoid that. It works for a while, but not forever. I now switch between standing and sitting on a kneeling chair and use a split keyboard to have a better posture.
There are lots of ways of making a living in creative technology. Maybe the first step could be to figure out which ones fit ourselves?