While I am not going to be able to come up with a diagnosis I believe I can point you in the right direction to get the answers you need:
At this point I think the best thing for you to do would be to gather up copies of all your medical records and travel to a large University Teaching hospital. At an institution like that you could be evaluated and treated by a team of sub-specialists who are at the cutting edge of their respective fields. The best thing about these large teaching hospitals is that consultations are available with Professors and leaders in their field by just walking a few steps down the hall.
In the USA the Mayo Clinic in Rochester, Minnesota is an excellent example of just such a place as this. That being said there are many excellent teaching hospitals all across the United Kingdom and I am sure that there is one near you.
I know that it is going to take significant effort on your part, but I believe that going to one of the "Medical Mecca's" is your best chance to – finally -- get to the bottom of what is going on.
Does this make sense to you?
I realize that this was not the answer you were hoping to hear but it would be unfair to you and unprofessional of me were I provide you with anything less than truthful and honest information.
Surely, you prefer that I tell the truth rather than what you wish to hear. Because it reflects very poorly on me unless you press one of the top three feedback choices, keep this in mind when rating my answer and please do not punish me for being honest. I understand that this may not be easy to hear, and I empathize.
Even though my answer was not quite what you were hoping for, please understand that my priority was to provide you with the most honest information. With that in consideration, I hope that you found my answer useful. Please click the excellent feedback button so that I can receive credit for my efforts.
Dr. Rick MD FACS