You could almost double your B-12. Many do best at about 1000. The normal high range is 960 or so. Minimal is usually about 400. The injured brain needs more.

Folate is helpful with the blood brain barrier and the myelin sheath over the nerves. Hopefully, the Delpin will do good for you.

Keep in mind that the RDA levels are minimums to prevent malnutrition, not optimum health. The normal ranges can very between labs.

I use Vitacost.com for almost all of my vitamins. Their house brand is good and affordable. They sell Now brand B-12 that my wife likes because it dissolves easily. They have good BOGO sales regularly.