Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
As per your complain burning under tongue on eating can be due to
canker sores or can also be due to abrasion caused by
injury with some hard food stuff, nothing to worry, you can apply a numbing gel over the burning area and do warm saline gargles..
The lump you have noticed on the left side of throat which is occurring specifically during eating can be due to obstruction of the duct of the submandibular
salivary gland which can be due to obstruction of the duct orifice by some foreign body or duct obstruction anywhere along the course of duct by formation of salivary stones or sialoliths..
Noting to worry, consult an Oral Physician and get evaluated and if required he can take a cross sectional
x ray and rule out the exact cause of the swelling..
In case of stones either manual removal or surgical removal depending upon the size of stones is done..
Hope this information helps..
Thanks and regards..
Dr.Honey Nandwani Arora.