I have trigeminal neuropathy and take a constant dose of amytriptaline however after two years I have started suffering with the severe facial pains?

Adjust medication. Trigeminal neuropathy can be terribly painful. Amitriptyline is a good choice, but you may simply need a dose adjustment. Some patients respond to switching medications to another nerve pain drug. Others require multiple different medicines to control the nerve pain. Maybe it is time to see your physician in follow-up and take another look at your pain management strategies.
Med change. Sometimes nerve pain medications stop working over the course of time. Consider changing the dose, changing to a different medication with similar pharmacologic action (a different tca), or switch classes completely.