Mate, two things:
1. Mate of mine was classed 3R over migraines (temporarily unfit for mil service, pending specialist medical reports) and after a spec medical report was reclassified to 1 (fit to serve), so I think you should be fine. He had about the same amount of migraines as you've had in your life and was about 7 years younger. He's currently a Reserve Rifleman so I think if he was alright with that, you should be alright with yours.
2. Be careful about what else you put down on your questionnaire. I was offered a position as a part-time GSO by my selection board but a week before my appointment date was Class 4'd because I have an allergy to peanuts. It was erroneously classified as severe when in actual fact it's mild, but as some very recent posts have alluded to, the medical appeal process is long, stressful, and expensive and I would avoid going down that route at all costs.