Hi welcome to Health care magic forum, you are not specifik about your age, and personal details. If you are a student, it could be due to
indigestion, exertion, food
poisoning,
anxiety,etc.
If you are a teacher either
hypertension, exertion, etc might be the cause.
Some people may get shaking hands, and body when they feel nausating , some may get blood tinge when they vomit. Some may get
vomiting due to leakage of blood in the stomach, due to hyper tension,
peptic ulcer, etc.
I advise you to consult a physician for examination , investigation, diagnosis and treatment.
Avoid taking more of spices, chillies, junk foods and oily foods. dont worry you will be fine, and thanks for caling.