How to cure my trauma being in an aeroplane?

I used to be so brave and not afraid of heights when I was a little girl. Until one day I saw aeroplane crashes on televisions, and I also experienced an unpleasant flight on one heavy rainy night, when the thunder stroked, the airplane suddenly went down a bit, which scared me until now and it turned to my no.1 trauma in my life. I'm a teenager now and always lie on my mom's lap when the plane shakes even a bit, I even cry when I feel so scared. I can never sleep and eat in aeroplanes since that trauma happened... and everytime I heard the word "aeroplane", negative things about it always appear in my mind.... I need help so bad..