As you've seen, everyone here is very informative, supportive, and helpful. As has been said, we've all pretty much been where you are. No one want to have a chronic illness, but having one does not mean the end of your life (or your activities). It merely means that you will have to make some necessary changes in order to manage that illness.
One of the things about Lupus (as Hatlady mentioned) is that it can mimic so many other auto-immune/connective tissue diseases. For this reason, it may take up to a year before you get a definitive diagnosis. Just insist, during the diagnostic process, that your doctors treat your symptoms so that you do not have to suffer unnecessarily.
It is good that you have done research so that you can be knowledgeable about your illness as possible and so that you can make informed decisions with your doctors. You are fortunate to be referred to an excellent immunologist/hemotologist...they are pretty much the same as a rheumatologist. If not, request that you also be seen by a rheumatologist.
We are here to provide answers, information, comfort, support and understanding. You are not alone!
Peace and Blessings
Look For The Good and Praise It!