It seems that you developed lacrimal gland infection
of lower lip.
Initially due to blockage of salivary duct there might be swelling.
Then it would became infected.
You should not wait as you developed large painful sored swelling of lower jaw. You should immediately consult dermatologist
for perfect diagnosis and treatment.
He may give heavy antibiotics with anti inflammatory drugs.
If needed, he may advise few blood tests and radiologic examination, to rule out other diseases.
I hope you got my answer, please follow it.
Dr. Ilyas Patel MD