Kathy, some people have mucus as a result of the digestive tract trying to protect itself from refluxing acid or bile. But others find they get copious production of mucus as a result of food intolerances and the actual feeling of refluxing or more than the normal production of acid can also be due to food issues.
You may want to try to get some testing done - although it's a bit controversial - on food intolerance issues using IgG (delayed response antibodies). Using those results, try eliminating foods and see if the mucus diminishes.
On 'biggie' that seems to produce a lot of mucus in many is dairy in any form - just a thought.
Welcome to the gastroenterology community! This could be related to the foods that you are eating. I would recommend eating a GERD-friendly diet which mean avoiding acidic fruit or juices, fatty foods, coffee, tea, onions, peppermint, chocolate, especially shortly before bedtime.