Your question has two aspects- increasing front side of head and not interested to food. Firstly we have to be sure that overall head size is increasing or not. We can do it by measuring OFC. If OFC is more in respect to the age and sex of the child then obviously it is a matter of concern. Localized increase in head size is usually uncommon. It may be a normal head shape but seems to be abnormal to you. Whatever the reason is, if head is actually enlarged in size either locally or globally, some other symptoms must be present in your child. The second issue is vomiting. I am not sure whether this vomiting is related to increasing head size or faulty feeding practice. Almost every child of an well to do family has this sort of vomiting problem related to feeding because they are always forced to eat. As you have mentioned another issue of head enlargement so these may be the consequence of a same problem or may be two separate issues. My advice is to evaluate the head size by a pediatrician because without seeing your child it would be difficult to conclude.