Charlie - Could I ask what takes you away from home for so long? If you are unemployed, isn't there some stuff you have to do regularly to do, in order to satisfy the system? Sorry, I've been very fortunate never to have had to work my way through that particular maze.
You seem very concerrned about your health, but seem unwilling to do anything forrmal about it - i.e. go to visit your Doctor to have a repeat blood test.
You could certainly do a home A1c test, but I would bet the farm no GP would form any diagnosis based on that. I doubt many would have understanding of it, he would have no idea how rigorous the testing conditions are, and even, he would have no idea who actually did the test. They can only make a true diagnosis based on tests carried out either by themselves, in situ, or in a recognised UK Haemotology lab.
Nodoby on this website can diagnose you with anything. Nobody. Members on this website will do their best to help others out, and to help them try to understand where they find themselves unexpectedly, however, where you seem to be right now, there really is very little anyone can do for you. There are too many loose ends. The actions all seem to lie with you.
Bottom line is you have to decide on your priorities.