anxiety meds for flying?

I have horrible anxiety attacks when I have to fly. I take Valium 5mg's and hour before I fly then again while I'm flying and so on. I always weigh the same, eat the same but it affects me different everytime. Sometimes 5mg's will do but I've had to take 20mgs before on a 1 hr flight. I don't want to o.d. Is there something out there I can try that would be more consistant? I have tried Xanex that had no effect. I don't have anxiety problems outside of flying. My family has moved across the country and I will have to fly a lot. Someone told me to have a drink and a Valium but that doesn't sound safe.