All of my workouts are 3 sets of 8 at the 75% and increasing by 5 lbs when its easy.
The reasoning for this is -max reps 3 to 5- tax the central nervous system which is weakened or damaged by the brain injury.
6 to 8 reps taxes more the muscles for growth and strength. Teases the cns a bit.
10 reps or more muscle endurance.
Im no where close to where i was, but am seeing progress doing the high reps thing so ill just keep working and see what happens .

When you dont overtax the cns it doesent matter how you feel the muscles can do the work.
Once you find your weight for reps of 8 or 10 you ahould be able to hit your numbers .

But at this point your job may be all your able to do and going to the gym might be too much for one day.