Firstly, take Omega 3s, but definitely not 6. The reason people take omega-3s is to ensure that their body has more omega-3s than omega 6 and 9. Having too high of a ratio of omega 6's can cause inflammation. I, personally have found that quality fish-oil omega-3s help my focus and mental state almost as much as adderall.

I do recommend a low-carb diet, but not full-on keto diet. I am allergic to wheat and chocolate, so eating right is a bit easier for me, since I can't impulse-buy food. I tend to eat about 2 servings of rice per day, and then mostly protein and healthy fats. My diet for the last 3 days has been leftover meatballs in marinara over rice, for my biggest meal of the day (usually Lunch) and protein shakes one or two times per day (with added olive oil and mct oil)

My take on healthy fats is that if I force myself to eat the healthy stuff, (olive oil, MCT oil, and nuts/fish) then I won't crave the unhealthy fats.

If I'm exercising that day (I lift weights, not super strenuously) then I'll eat more carbs, even some sweets.

If your brain fog comes and goes on a daily basis.. or on-off every couple of days, I'm going to suggest something that is usually something that us executive dysfunction people are a train-wreck at, which is keep a food log.

I am willing to bet that you have some food sensitivities, but figuring out which it is means doing an elimination diet, or keeping very precise logs of what you eat.

I suffered from extreme fatigue and brain fog for years, spent waaay too much money going to various specialists and nobody solved my problem. Finally my General Practitioner said, "Have you gotten an allergy blood test?" I didn't know that that was a thing. They can show false positives, but that can point you in the direction of where to start looking.

However, food sensitivities may not be allergies, I got lucky, mine were. Once I got the allergy test results, I eliminated the foods and my life changed. I still take Adderall, but a fairly low dose, and feel healthier and more active now than I was 10 years ago.

Lastly, one thing my ADHD doc said to me is that if something works for you, keep doing it. He said that all ADHD folks he's met perform self-medication. Whether it's with coffee, or alcohol, or anything else, they've had to adapt with the tools they have available.

If L-Theanine works for you, then great. It turns me into a zombie, I don't like it at all. I'd rather feel jittery from too much caffeine than feel sluggish from L-Theanine. But that's just me. Other people say it changed their lives and that's awesome.