I've had migraine headaches for at least 29 years.  i've tried everything. What are chances of disabi?

Special dentist. Find a neuromuscular dentist. Migraines often have their origin in a bad bite, with resultant muscle fatigue and spasm. The bite affects posture, jaw closure and muscles cannot relax. With advanced computerized diagnosis and ultra low frequency tens, a bite appliance may help your symptoms resolve through creating a bite that allows the muscles to relax.
Consult doc. Disability determination is based on inability to work productively. You will need to confer with your doctor and an attorney who specializes in disability to determine your status. If you have multiple conditions (comorbidities) that can impact your ability to work, you may be a better candidate for disability compensation.