I find this approach somehow works for me - Do things at least 30 minutes daily for 2 weeks. No matter how hard it gets you just do it. By 2 weeks, you get used to do certain things and feeling confident about pushing yourself more to learn something new and new topic. It's also my approach to working out as well. At first I started with 30 minutes to these days an hour/daily. My goal is being comfortable doing 2 hours/daily without feeling too exhausted. So, maybe try that and see how it works for you.