Migraines and Work, any advice?

I've started suffering with migraines and have had about 5 this month they have been so bad i have to miss work. Missing work makes me feel awful and guilty as I feel like my co-workers and boss think im slacking and skiving. I've been to see my GP who prescribed me medication which relieves it sometime but im starting to feel like my main problem is missing work. Has anyone got any advice about missing work?