The trick to building discipline: stick to your projects more often than you quit, so your actions start overruling self-defeating thoughts.
So how make sure you stick to more of your projects and habits
Make them feasible. Start small.
Write a couple of sentences in your journal every day.
Write short articles.
Walk for 5 minutes.
Do 2 minutes of breathing exercises.
In the long run, you’ll probably have to build up volume and intensity. But first, start small. Build trust of completion. Become disciplined.