It's very sensible to be afraid of it.
My approach is always to take some time to realy think about it. I just ask myself the question "do i realy want to do this?", and i take all the time i need to think it through and find an answer. No rush, nothing pushing me to either decide in favor of it, or against it.
Sometimes the answer is "no, this is not a good time".
But once i decided that i realy want to go there again, i just do it. Regardless of fear.
I just approach it as if i've been waiting in line to board a rollercoaster ride. Waiting there, seeing the train coming and going, hearing the noise, i had all the time to back out of it. So now it's my turn to board that train, i may be a little intimidated, but no....there is no going back now. Not anymore. The time has come to just go, knowing you'll definately still be there N-minutes from now.