Re: It was like DRINKING BATTERY ACID! Did I damage my esophagus or stomach lining?

 Oxidizers can burn the tissues. To make matters worse you vomited it back up. NEVER try vomiting up caustic substances since as you found it will just burn more on the way back up. Caustic solutions should be diluted if ingested, not purged.

The good news is that the damage is not likely permanent. You can make a tea with a mixture of slippery elm, comfrey root and licorice root boiling the mix for 20 minutes covered, then steeped until cooled. Strain the tea and sip on it throughout the day to help sooth the inflammation, protect the throat and intestines and to help promote the healing.