You are lucky to be able to manage your own risk :-)
I haven't been able to find a doctor to sign me off (I have about 3 seizures a year - 99% of which are pretty much predictable and, like you, when I am tired/just woken up/late at night). You are very very lucky to have found one so understanding. Basically if someone is going to sign a form saying they are responsible for our lives they have to be an expert at epilepsy, at skydiving, and at knowing ourselves! I always thought the only person who could (and indeed should) sign such a form would be me! so thats what I did....but now I'm not allowed anymore and it has to be a doctor and of course they don't know me and don't "get" skydiving.
I miss skydiving a lot and miss my friends, but am so happy to have had the years I did, albeit that there was a bit of uncomfortable white-lying going on for me to pull it off.
Good luck :-)