Dryness of mouth can occur due to many causes. Medicines to cure cold; BP medication; diabetes; stress, dehydration
etc are some of the causes. Menopause
; due to changing hormonal levels can result in dry mouth
. Burping and a feeling of lump in the throat could be due to acid reflux
Sipping water; avoiding caffeinated drinks which dries the mouth and chewing sugarless gum will help increase salivary flow and prevent dryness.
Also lifestyle changes and drugs to prevent acid reflux will help ease the burping. Hope this helps.