Try to eat or drink every 2-3 hours
Try to eat something with carbohydrates and a little fat at bed time so that the food carries you through till the morning like an indian mithai, pastry, cake, kulfi
Use a toothpaste with mild mouthwash
1st thing in the morning before brushing your teeth just eat something, it may be a dry toast a biscuit and then brush your teeth.
Try to be busy in some activity or other so your mind is off your nausea. It helps. Potting plants, learning something new like music, singing.
Mint leaves, ginger in any form & citric foods secede morning sickness