OP you have my full sympathy and there is NO way I could remain with him. This was my entire childhood so I know first-hand what it's like as my adoptive mother had Munchausens and adoptive father M-by proxy.
Not sure about GP's these days but AM had test after test, even surgery, for her ailments but funnily enough 'nothing' was ever found. Of course, medical testing is more advanced these days so I wouldn't expect any GP/Surgeon to do a surgical procedure without some kind of proof, but I've spoken to various GP's over the years and can tell by their expression they have agreed with me, even though it's unethical for them to comment.
My first childhood memories she was on her deathbed with only hours to live....strangely enough she lived to be 85yo and outlived all her family. Lost count of the number of times I received a call to say 'get her quickly, she won't live much longer' but miraculously she pulled through only to repeat this process again a couple of months later.
Call me heartless but I gave up rushing to be there as I knew the script, there is only so much you can take and by now my own young family was more important than driving almost 9 hrs to yet another 'false alarm'.
For a long while I used to think maybe this time she 'is' sick specially if she had just had another major surgery....but she had the doctors fooled too.
and
you'll need them both!