I have to agree with narcsage on the comment about trying it in a foam pit...they are amazing! I actually joined my universities gymnastics club team. see if there is a local club team that you can join. Maybe at a YMCA or rec center near you.
One tip that I can give you is just go for it. I had the same fear. Then I just jumped real high and reached for the stars, tucked up into a tight ball and grabbed my knees. Before I knew it I was on my feet.
Try with spotters first though. once you get it by yourself...it will be much easier...trust me. Just keep persevering and don't give up! YOU CAN DO IT!!!