Hey there stephanie
Talk is cheap, so talk away

there's nothing to loose there, just don't smother your friend with your issues, unless she asks, and you are sure she can handle them. As far as picking up that phone, I can relate to that. It's a very scary thing to have to do, it's almost as if you are making an admission that you have been hiding this deep dark perverted secret to a complete stranger, hey wait a second, you are

well it's not perverted and it's not dark

Don't worry about your work schedule interfering, with therapy, that's putting the cart before the horse. Talk to the therapist and make an arrangement, after all I assume you will be paying for the therapy, so the therapist should be a little flexible.
Seriously though... Make that phone call! People barging into your office while you are on the phone is a lame excuse don't you think. Lock your door, put a chair under the door handle, better yet go to a pay phone. Just think of it as the first step that begins your journey. It's a hard thing to do but your journey can't start without that first door being opened.
Go for it.
Steph