1. For me it's hard to stay motivated learning a new technical topic if I can't connect it to some plausible future where my life would benefit from the knowledge. If I’m not addressing any pain points then the drive to study just won't be there.
2. Realize that there’s going to be an overwhelming amount of resources and tactics you can use to learn the topic. But they’re all not created equal and some may get you to your desired destination faster than others. This is highly personal; not every method of learning works for everyone (ie: I dislike learning theory through videos and lectures, highly prefering technical books instead).
3. Find a group of people that's at least slightly above your knowledge level in the topic and learn through osmosis. While I was able to pick up the foundations of infosec on my own it wasn’t until I was learning with others, especially while preparing for certification exams, that I got to learn more of the intricacies of the topic. Learn with others that have a similar drive as you.
4. Set weekly goals and dates in the future that you really need to test your knowledge to see if you understand the material. Security certifications, while I was a bit rebelious against at first, served this purpose for me perfectly. I’d set weekly goals to learn material based on a courses' syllabus and every few months there was the ultimate test to show I actually grokked the topic, which huge burst of hedons along with it (if I passed, which has been a 3-exam streak for me so far).