Hello and Welcome Limarie :lol:
One of the reasons that Lupus is so difficult to diagnose, as you mentioned, is that its symptoms can also be attributed to so many other diseases. Your tests can be negative this month, but positive next month! Also, doctors often have to wait until your symptoms worsen or new symptoms appear before they are able to made a definitive diagnosis.
Just as it is difficult to diagnose Lupus, it is equally as difficult to say that your symptoms do, in fact, indicate Lupus. They can also indicate several other conditions which are also auto-immune disorder and/or connective tissue diseases.
As Sits-in-the-corner mentioned, not having a diagnosis should not stop your doctors from providing treatment for your symptoms. Especially given the fact that many of the treatments are the same for many of the auto-immune disorders. So, while you are in the "diagnoses merry-go-round", insist that your doctors treat your symptoms.
Regardless of what you are diagnosed with or, even if you are not diagnosed, you are very welcome here! We will try to help you in any way that we can and we are always here when you need help!
Peace and Blessings
Look For The Good and Praise It!