First of all, God doesn't hate anyone. And to believe that you're being punished is not helping in any way whatsoever.
There are people who can read auras who can see a disease in the aura before it manifests in the physical body but I'm not sure if they can see if the disease is genetic. You yourself can find that out can't you? If you have a certain disease find out if any of your forbears had that same disease and you can always do some research and find out if it is genetic or not.
Shamanically speaking, negative entities can cause physical illness and can deplete your energy terribly. As well, negative magic can also cause illness. IMHO both of these causes are really quite rare. You would need to see people who are knowledgeable about these things to get some help in dealing with these issues.
Why do you say that the doctors no longer care? Are you saying that you've been to more than one doctor and they can't find what is wrong with you?
You either were or were not energetically cleansed by people online last year - which is it? Personally I don't believe in doing that sort of work online - you're much better to find someone who's knowledgeable (like a true practicing Shaman, for example) than trusting someone you've only met online.
Your anger comes through very clearly and anger itself can cause physical illness if you harbour it inside yourself long enough. I would respectfully suggest that you need to work through it and release it.