Having really dry mouth i have to excessively chew food to swallow & sometimes have to drink it down with water. my tongue sticks to roof of mouth?

Find the cause: Dry mouth can cause many intra-oral problems, so it is best to find out the cause quickly. It could be a change in medications or an underlying systemic condition. Best thing is to consult with physician or dentist to determine the root cause of dry mouth as it can be very destructive and uncomfortable.

Many causes: While there are many causes the one i find most common is dryness or diminished salivation due to side effects from drugs including many over the counter types like anithistamines. In fact, the most common side effect secondary to prescription drugs in dry mouth. Talk to your dentist or doctor to find out for sure.