Welcome to HW. Sorry to see you here, and sorry you are having problems getting the data you need for further planning. I really don't know that you can do anything more before the doctors appointment. When you do get there, I'd really make him explain to me why the rash, etc. hasn't been tested to see what it is. I'd make sure I understand his reasoning and that it makes sense. He may know things you don't, but you gotta ask for explanations. Others may be around to further answer.
I cleaned up my misunderstood mess here. I completely got confused about the biopsy or psa tests. Sorry for any confusion or making you worry if I had lost a wheel there...