Please stop trying to diagnose a physiological injury, axonal tearing, white matter, etc. This is just anxiety. No specialist can tell you the answer you are looking for. The standard is to treat the symptoms. There is no way to define the damage to treat the damage.

A DTI MRI will not tell you what was damaged. It will just tell you that your brain is struggling in a specific area. A DTI will only image symptoms of an injury, not the specific injury.

40 days of rest is a very short time as brain trauma is concerned. Rest alone is not a treatment. You need proper stimulation to encourage good brain blood flow. You also need to deal with anxiety as it causes a cascade of bad chemistry through the brain.

You could be simply suffering from depression. Have you seen a mental health specialist/psychiatrist ? Depression can cause severe brain fog. Believe me. I was in a severe fog from depression 32 years ago that lasted for over 6 months. That is why I was told to start the vitamin and supplement regimen. B-12 was a big part of my recovery. It took 8 weeks to see a difference. Not everybody responds the same as I did. If anxiety is a factor, other therapies may be needed to overcome the learned anxious thoughts.

Stop doing internet research. Axonal damage, white matter, etc. are all just terms you can use to increase your anxiety. The more you find terms like that, the more likely you will struggle with anxiety.

So, please seek a professional diagnosis.

My best to you.

Mark