Unstable

So im 14 and in high school and im currently taking prozac for depression and anxiety and im at the max dosage. I might be unstable and im trying to stay home from school tomorrow because i feel like id starting crying or id snap at someone and i dont know what to do. I was diagnosed with depression and anxiety but sometimes theres these changes in my moods. One second i could be perfectly fine and the next ill be super irritable and angry. I have an appointment with a therapist tomorrow but idk what to do. Ive also been getting stomachaches more frequently and headaches. Any advice?