Hello and thanks for the query
You have explained one reason for your problem in your query i.e. stress
. Stress can cause these type of symptoms along with high blood pressure
. Other reason can be dehydration
as you have not eaten the last two diets. Due to gastric juices there may be inflammation of the track that gives you the feeling of nausea
. Take complete rest and take light and fresh food (semi-liquid as much). Drink plenty of water and relax you mind. Sava Asana will help you a lot.
Hope this will help you.