Prenatal vitamins is never a replacement or to be used as a meal replacement. Drink milk, maternal milk or some drink like milo/horlicks as a temporary “meal”. But never let this be a norm or sth u regularly turn to. Nutrition is v impt during pregnancy. It’s for both u and baby.
Pre natal visit can be taken in the morning only. Perhaps you can have materna milk twice a day so that you dont keep ur stomach empty by dinner time. You can also make some hot chocolate with biscuits or bread or fruits.