Browse through the Rescue Squad and Hacking sections of the forums here. Read about other people freaking out sitting in a corner with their "bricked droid". Read a couple guides how to root, what its about, etc. Two paths to take....read, take your time, and understand what each step is doing...or just jump right in. I've seen both go good. And both methods have some struggles. In the end either method works out so don't panic if you get stuck. Your phone will be fine. Usually.
For the op, on a mac: You need to find someone who has a Windows PC. Read up first, and it shouldn't take more than 30-60 minutes to be all set.