Migraines every day at the same time

Does anyone else have migraines at the same time every day? My migraines started when I was about 9-10 years old. They didn't happen very often then, but they'd start with an aura, blacking half of my vision out and they'd quickly turn into painful headaches, nausea, light and sound sensitivity and would only go away with medication and a long nap. They've become more frequent since then, I'm now 21. it's strange, I have a migraine, every day at the same time for about two weeks, then they'll just stop for about two weeks. I'll have a migraine or two during those two weeks and then the cycle will start again. Sometimes they're at 11, and then the next cycle they could be at 1. But they're usually about the same time every day. Stiff neck, nauseating migraines that just completely put me out for the day. I have been diagnosed with chronic migraines, I was prescribed Rizatriptan but it made me feel so drunk I couldn't even lift head and it did nothing for my headaches. Now I've been given Propanol to take daily to prevent them, it doesn't work. They come without fail. I went through a long period when I was 14-16 where Drs we're confused with what I had. Constant neurology/oncology visits testing me for everything from cancer to lupus. Multiple MRIs. They never found a thing. Not even anything related to my headaches. Have any of you experienced something like this?