About 15-30mins after i brush my teeth & use mouth wash, i get for a lack of a better term a type of film in my mouth. what causes it?

Probably alcohol: Many mouth washes have alcohol in them that can dry out the mucus membrane of the mouth giving the feel of a film. Try a mouth wash without alcohol.

Might be: A protective film from either your toothpaste very common and beneficial with colgate "total" or from ur mouthwash.

Either: Some types of oral rinse has caustic or highly invasive substance to improve its effects. Also some toothpastes has abrasives that might cause that film . Consider replacing either or both toothpaste and mouth rinses and remember to brush your tongue as well.