Unfortunatly for you, most medical tests don't show anything most of the time. parasite analysis comes back almost always clear even if a massive infection is present. There's no reliable test for candida overgrowth. Liver function tests are not reliable, as a severely clogged and weak liver can show normal results... And so on.
If your problems appeared after a long Antibiotics use, you are very likely to have a candida overgrowth. Also, Antibiotics are hard on the liver.
If you want to restore your health, use a whole and natural approach. Treat the cause. Most people here have the same issues to start with: candida and/or parasites overgrowth, leading to weak liver because of the toxins they release, weakening the whole digestive system, allowing them to proliferate even more. And then you've got yourself a VIP pass for any major disease out there.