I read that you shouldn't mix Sodium Benzoate with anything that has vitamin C in it(orange juice has lots of vitamin C), it forms a carcinogen, so I mixed it with water.
Still feeling improvements. Anhedonia seems to be better now(songs sound better), motivation as well. Hopefully I'll keep improving. It seems to be very subtle. Sarcosine worked great for 3-4 days and then dwindled off, hopefully this doesn't happen with Sodium Benzoate. I took Sarcosine for over 3 years but it didn't make a huge difference(only helped memory), was expensive and messed up my sleep.
I have a slight headache. By now I've downed the entire 500 mg. I think also my talking to myself or mumbling rather has improved. I feel more in control in general.