Scared to do my back handspring on floor!?

heyy guys i got my back handspring on my trampoline and on a squishy mat about a year ago but im sooooo scared to do it on the floor!!! I just can't get myself to jump back. I'm a level 4 gymnast and i have a competition on April 18th which is coming up reeeaallyy soon and i have all my skills except for my round off backhandspring but i can't compete unless i get it by then. Somebody PLEASE help mee. I'm freakkin out right now.. I dont know why im so afraid. Can anybody give me and tips and/or drills that i can do?? thankss in advance(: