Will look into that. I have just started researching things like BDNF which promote synapse plasticity and neurogenesis in the hippocampus, I feel like I've opened a door to a whole new world. I'll do a PubMed seach on all the foods you've listed. I remember starting to eat a bunch of walnuts because some source said that it contained DHA, but now another said that it doesn't and rather was a good source for ALA which in turn can be converted by the body to DHA but not very efficiently.
I'll dig into it, so much to learn!

I'll try yoga for sure, especially when I feel confident enough in my energy levels to walk more than an hour at a slow pace each day. As of now I feel like I can increase my exercise a whole lot more through walking before taking on a new discipline.

Do you think that a symptom returning is a gradual thing? Because sometimes I can feel slight hints of dizzyness or eye strain when reading or watching videos without it being very uncomfortable. Do you have a zero tolerance policy against all symptoms? I feel like I know that some symptoms are more common when I have some anxiety than others and thus I try to not get riled up when I suspect that a symptom might be coming with a lash of slight anxiety.

The executive functioning thing: I've noticed that my brain gets tired and notice signs of feeling off or a little dizzy when I've been doing things that require my brain to exercise selective attention focus while dismissing something else. This includes ignoring the lyrics to a song playing on low volume in the background while having a conversation with someone or shifting the focus from typing out something on the computer to a conversation with someone close to me repeatedly, at a quick pace. I am a psychology major but I haven't spent a whole lot of time researching executive functioning, so if my understanding of the concept is off that is why.

Regarding going to sleep when I feel sleepy: I am strange in the sense that I never go to bed when I feel restless or have anxiety. I just stay up for hours upon hours and procrastinate sleeping - in the past this hasn't caused a lot of problems because it's usually just one night in a row of several where I sleep okay, but now I feel like I can't give myself the freedom to risk messing up my sleep over something stupid. This is why I've tried establishing a routine of going to bed the same time - if I don't have one I'll move my bedtime further and further into the morning only to realize one day that I have to move it back. This results in poor sleep across the board.
I actually took your advice on longer naps a couple of months (or weeks, I don't know - time seems to go by differently with my PCS) ago and since then I think I've been sleeping better.

I haven't been checked, no. I've had pretty bad experiences with neurologists and doctors, so I've resorted to just keep at it with my current routine since I've been improving pretty steadily anyway. Routine and patience has been the two factors that seem most effective for me - trying to sleep well, not exposing myself to too challenging stimuli, eating alright, walking a little bit each day and meditating have made me significantly better over time. I'm sure I could be helped by a professional if I could just find one who wanted to help, but up to this point I haven't had much use for them since they don't seem to understand.