Hi..
Welcome to HEALTHCARE MAGIC..
As per your question it seems that pain during the first few bites of eating food severe pain that diminishes is pointing towards neurotic pain like
Trigeminal Neuralgia or Tic Doloreux..
Trigeminal neuralgia can occur due to disturbances associated with the fifth
cranial nerve that is the
Trigeminal nerve..
You need to consult a Neurophysician and get evaluated for the exact cause of the nerve induced pain as there can be some causes like the most common one is a large artery impinging over the nerve causing damage of the Myelin Sheath [ a protective cover over the nerve] leading to severe
electric shock like pain..
Other causes are disorders like Multiple sclerosis, tumour compressing the nerve, physical trauma etc..
Get a detailed evaluation and tests like MRI SCAN can be done to rule out the underlying cause and treatment of the same can relieve..
You can be advised Neurotic painkillers like Carbamazipine, Gabapantin, Baclofen etc..
If there is any artery impinging the nerve Microvascular decompression in which the compression over the artery is surgically removed is done..
Other procedures like Balloon decompression,gama knife
radiosurgery, glycerol injection etc can be done to relieve pain..
Hope this information helps..
Thanks and regards.
Dr.Honey Arora.