Statement of Physical & Certificate of health London

So I’m trying to applying for the 26’ entry and I’ve noticed it’s really hard to get my gp to fill in the necessary medical documents (as I have some underlining conditions) they literally said go to a private gp (which is frustrating). My question is what’s the process like with a private gp has anyone experienced it what steps did you take?
Additionally with regard to X-ray how did you guys do it? As I’m struggling here

by abobaker55