First, I would seek the advice of a doctor who has a specialty in PCS. GP's should not be prescribing antidepressants. You need to find a neuropsychiatrist or specialist in physical medicine and rehabilitation who has expertise in PCS. SSRI's take weeks to become effective. They can also be disruptive to brains as they change the chemical processes related to neurotransmitters.

Are you on any other medications? Allergy meds?

Be very cautious about letting a GP mess with your mind.

Maybe your pharmacist can give you some advice. Maybe a referral to a specialist.