How good are your sleeps? Are you drinking enough water?
I know that I get brain fog if I sleep poorly or forget to drink enough water.
For coding, I try to explain to myself exactly what I am trying to solve using the most simple explanation possible.
Usually, the program will perform a series of steps. I work on each step, in code, until I solve that step. Then I move on to the next step. Divide and conquer.
Like the other person asked, have you sought out professional help for any possible medical issues? If you have ADHD then a professional can give reliable guidance on how to compensate for the main ADHD symptoms.
Good luck! You CAN do it!!!
The cool thing about 1310nm light is that it will pass down either multimode or single mode fiber.
At that short of a distance, you should be able to use MM 1310nm SFPs.
As long as the SFPs can do the signalling speed needed by the link then I see no reason why it shouldn’t work.