Thanks for posting your query at DoctorSpring.com
I am Dr.R.K and I am pleased to assist you.
It is not only totally stopping the sugars but also reducing the calories by 50% that is responsible for your symptoms like headache, poor concentration, irritability, lack of energy etc.
And your stressful job is worsening the symptoms.
I would advise you not to stop sugar cold turkey and cut the calories by 50% abruptly. Instead you can gradually reduce the intake of sugar and calories over a period of days to weeks allowing your body to adjust itself to the dietary change.
I feel that answers your query.
Let me know if I can assist you further.