Cheeks and under both sides of tongue sour/bitter all the time. irritation/swelling and thick whiteness in back of tongue. could this be acid reflux?

Whiteness tongue: If the white areas on the tongue are like cottage cheese and wipe off and under them is a reddish base, you could have candida oralis. This can be easily treated with an antifungal. Reflux would have other symptoms like acid brash (acid taste on the throat after eating when you burp and you almost throw up acidic fluid). Try brushing your tongue both sides and the top (dorsum). Might help.

Possible: Acid reflux can have several side effects. See your dentist and/or physician and have them take a look.

MAYBE.: Most of the times you should feel your reflux and this would be a confirmation that the problem on both sides of your mouth is due to the "burning" of the acid, but you should check also for a possible yeast infection in which case you should take anti fungal medicine.