I have trouble finishing my 180 i can do the 180 but i cant rollback because of my pedal i push it accidently and it stops help me

Wow.. if You have a brain stem You can figure out what your doing wrong. try harder,the question is self explanitory.

go faster, its scary at first, but when you do it youll realize that you spin easier, and when youre rolling back, make sure you turn (the way youre comfortable most) and pedal at the same time.