I have gotten migraines like that - and they even go into the arm... but I would surely go and get checked out. Migraines can be very visual and my my mom used to only get them in her arms. My visual clue is a sparkly thing though - but get it checked out.
Ask your doctor about getting an MRI. Do you remember if you may have had an injury to your neck or spine 3 years ago? Start documenting your symptoms - what time of day they happen, what you may have done that triggered them, such as food you ate, standing in bright sunlight, anything at all. You may find a pattern.
Doctors tend to take you more seriously when they see it in writing.
Your blood pressure may be rising or falling during your headaches. Get a blood pressure cuff and keep track of your pressure daily for a week or two (write it down), then see if it is very different during your symptom attacks.
Yes. I went and had an exam a year ago and there was nothing abnormal.
It definitely sounds neurological. Peripheral vision loss can be tumor or glaucoma. You need to see a neurologist. It could be serious. Have you been to an ophthalmologist since this started?