How to stopp being scared of the ball? [[soccer]] defense help?

imm a defender in soccer. wen someone trys to go make a goal from thee opposing team i run next to them, but they juss juke me cuz i am afraid to take it away from them. imm afraid bcuz a week b4, we had a turnament and i went to take the ball away from a guy but he kicked my ankle insted of the ball and i had to sit out and i wuz in pain for lyk a week so i ***** really walk for a week xcept limping.. and my mom wants to take me out of co-ed soccer cuz of that. she says the guys will hurt me to much, but if i join an all girls team they wont. so i need help on how to prove to my mom that i can do just as well as they guys without getting hurt. so anyone kno how to be a good defense and not be afrain of the ball???