Anyone having trouble with heartburn that is mostly burning in the throat and mouth? I want to believe this is just part of anxiety. It is bad at night. I also wondered if this could be lexapro?

So sorry to hear your are having heartburn so badly. I've had the same for years and may have some things that will help.
First, no food after 6 p.m. Don't over eat!
No water after 7 p.m. None! Nothing to eat or drink after 7, at all!
Get Prilosec OTC and take it for 14 days. It had very few if any side effects and just makes it so much better. Be sure to take it mid afternoon or just before dinner. It may take a few days to start working really well.
When you sleep, try to lay on your right side.
Also, something I have yet to do but know it works cause my daughters is done is: raise the head of your bed up 6 inches. We used the bed risers at just the head board. Found them at Wal-mart in the closet organization section. You only need 2 but they sell as a 4 pack. Concrete blocks work too.
If this doesn't give you some relief, see your doctor! The acid in your throat and esophogus isn't healthy and he might have a better idea of what will help than me. Wishing you well and a good nights sleep, soon!

Lea