My brain is running a thousand miles a minute

I am at the same time, excited and terrified.  I have my first appointment with an endocrinologist tomorrow and my emotions are all over the place.  I am of course excited and one line from the Phil Collins song, In the Air keeps going through my head.  "Well I've been waiting for this moment for all my life, oh Lord."  At the same time I'm terrified.  This is a big step for both Dee and myself.  Plus what if the blood  tests find some reason I shouldn't be on HRT?  Would I be able to live with that disappointment?  I don't know.  I just don't know.  I'm trying to think positive but that thought just keeps nagging me.