Hi.. Thanks for the query.. As per your complain it looks like you have burnt the mucous membranes of your mouth and throat with excessive heat present in hot sweet potatoes leading to burning and blistering of the mucosa.. For relieving pain caused due to burning you can start gargling with numbing mouthwash containing Lignocaine.. You can also do warm saline gargles.. Suck ice lollies and drink plenty of cool water.. You can take Sucralfate to coat the ulcers or inflamed areas in throat and food pipe to prevent further damage from the acid and foods.. You should take soft, cool and bland foods.. In case if there is no improvement in 3-4 days consult a Physician and get evaluated.. Hope this helps.. Regards.