Sleep. Your body requires rest.
Fruits & vegetables. You don't have to be 'vegan' or 'vegetarian': my motto is the more fruits & vegetables I consume the better. Juicing is a great way to consume large quantities of these foods. People give me the o.0 stare every time I mention that I get 'high' from kale--along with other dark greens and fruit.
Learn about other fields / domains that interest you. Find less technical intro books and find ways that you can apply simple algorithms to compute things or program systems that aid in automating and managing things in that domain. Create a domain specific language (DSL) for assisting in thinking about and computing things in a domain. These things should be interesting to you and potentially beneficial to your life! Start small, stupidly small, and just explore and have fun.
Build a discipline of studying and practicing. Shit takes time, and if you don't put in the time you won't get there. Build the habit of regularly spending deliberate study and practice time. Plan your trajectory and track your progress & velocity and adjust regularly.
Nootropics and other supplements: (ar)modafinil, racetams, artichoke extract & forskolin, choline, amino acids, creatine, etc. I am a believer in no biological 'free lunch', but it can be fun to explore these on your own and form your own beliefs about them.