How can I not freak out during Airplane Take off?

I am 31, have never experienced take off or flying in a plane. Going on a trip next week and I'm petrified, I mean absolutely anxiety ridden over this small part of my trip, take off. I hate roller coasters and going fast. I don't' know how I'm going to not freak out when the airplane starts to travel down the runway and climb. It's not the safety I'm worried about, it's the feeling, I can't even ride a ferris wheel. My doctor is going to give me a sedative, will that actually work??? Please give suggestions!!