To whoever it may concern, i understand the desire to medicate to be able to focus better and work more. I had that desire too. Still have the desire. And I did try some meds but they were giving me massive headaches. I learned then that my problem was not lack of blood flow in the brain but lack of relaxation and balance in my life.
I could probably write a book on how to hack your life. And you may think that my life is perfect or something and I can work 16h/day and stay focused. I don't but I won't go into the details of why.
I will tell you in a bullet point list how to achieve much better focus, mental clarity and improve your overall life and your mind. Don't have the mood to give anything other than brief explanations.
1. Learn Reiki - start with Usui, continue when is OK with Karuna and then Shamballa. All are Reiki systems. Try to find a Reiki Master that is not a complete newbie. Also extremelly important ASK HIM TO WORK ON YOU SAVEERAL SESSIONS BEFORE THE ATTUNEMENT. If you feel absolutelly nothing - no heat, no improvement in your state, no energy flow throughout your body, or you feel unpleasent or a need to block him or protect yourself from him - move on and find another. There are other energy systems out there but Reiki is probably the easyest t start with and use.
2. Practice Reiki a lot for the 1st year. If you can practice maybe 4h/day for first 6mo-1yr would be great. At a minimum you want to practice at least 1h/day every single day. The more you practice the higher your energy levels will increase.
3. Keep doing Reiki as a way of life and try to have at least 1 Reiki session/day though I would recommend 2 sessions/day (morning after you wake up and evening before you go to bed) + short booster sessions (15min) as needed throughout the day.
4. If time allows it and you like this stuff, you can learn other systems too. Whether is Tai-Chi, Chi-Qong or whatever.
5. Aim not for tension and mental agitation but for relaxation, clarity and serenity. Contrary to popular belief, concentration is not an act of stimulation but an act of relaxation and of silencing your thoughts so you can fully focus on one thought/action. Most meds are neural irritators/stimulants. Coffe is an irritator too.
6. Do experiments with food, try to eat what gives you the best state. A good amount of raw food is a good start. I'm not saying to go vegan, just eat a lot of raw foods, veggies and fruits. Also when it comes to meat you might want to reduce pork and such meat and eat more fish. As energy boosters in the morning or when needed you can have coconut or pineapple. Also start your day with a glass of water in which you added half a lemon's juice.
Now you may think Reiki and energy work and all that is bullshit. If you actually practice it for an entire year, daily, at least 1-2h/day and after a year you feel no energy, no effects, no improvement and think you wasted your time, I will accept your opinion that you may think it doesn't work. Otherwise you're basically just an opinionated idiot who never tried the thing but thinks he knows it's bullshit.
If you really want to change your life, you don't want quick fixes like meds. What you want is a better lifestyle.
Also you want to work on discovering and understanding youself at a deeper level. This is really powerful.
Related to knowing yourself is healing your obsession with money and posessions. I am not saying is bad to have money or have things. What i am saying is bad to make that into something bigger than it is and is bad to program your mind that lots of money and a bunch of posessions are a requirement for your happiness. There is a massive difference between living your life frustrated and obsessed that you don't have what you want or enough vs. living your life not needing anything but working out of pleasure and having things despite not needing anything. I can enjoy a Lamborgini just fine while i am in a state of indiference towards whether i own one or not, whereas if i am obsessed and frustrated I don't own one will just push me away from happiness and condition my hapiness.
Have fun!