I suggest you be honest about drinking. Just say you suffered a concussion and are taking meds that both preclude drinking. If your co-workers have a problem with that, it is their shortcoming, not yours.

The foggy mornings can be simply not getting good sleep or not getting sleep where you are breathing properly. Sleep apnea can be made worse by concussions. The tri-cyclic antidepressant usually used for post concussion insomnia is amitriptyline or sometimes nortriptyline.

I take gabapentin to help my mind and body relax.

A single B-12 daily is just the start. What dosage and version of B-12 are you taking ? 1000 or more methylcobalamin B-12 is a good start but 2500 mcgs would be good. A B-50 complex, D-3 and magnesium are all important.