504 Plans and Hemiplegic Migraines

Hi there.  I'm a senior in high school and am fighting with the school district in Colorado to get a 504 plan because I am starting to struggle in school.  They say my grades are too high and that I do not miss enough school, which is all based on last year.  In the past three weeks I have missed 11 classes and my grades have started to drop.  The school had to rearrange my whole schedule so that I could take my AP classes in the morning because when they were in the afternoon I was missing them.  I also had to drop my AP Physics class and move down to regular which is the first in 4 years for me.  When I do not have a migraine, my medicine does greatly affect me.  I become depressed and can't concentrate because I tend to zone out and don't want to do anything.  If anyone has dealt with a 504 plan and could please offer some tips or suggestions I would greatly appreciate it.