Thanks for your query.
Your description shows you have tension headache
due to muscle strain
.You are probably going through kind of stress. These symptoms also constitute Panic attack
, when someone has a panic attack, that person feels a sudden, intense fear that can't be controlled.
If you have been working strenuously without break then it is the time to take a break and calm yourself. Continue your regular exercise and try meditation or yoga to keep yourself calm.
I advise you to visit your doctor to exclude Gastroenteritis
and Acute kidney failure.
Hope it helps.