I suffer from daily migraines like my dad and often i am unable to coherently form sentences, forgetting where i am/what i was doing; is this normal?

See your doctor: Migraines depending on their cause and duration can be responsible for cognitive symptoms, but not necessarily. Check with your doctor to figure out the etiology of your headaches.

Classical migraine: Migraine can be a rather protean complex and what you describe is entitled: "dysphrenia hemicrania transitoria", a period of confusion and aphasia either during the prodromal aura or within the main headache itself. This is a manifestation of the "spreading depression of leao" and is reversible after a time. Best approach is to prevent these events by prescription or otc prep.