What could possibly cause purple dottie rash all over the body and extreme weight loss, depletion of platelets? also depletion of blood causing a need for both blood and platelets transfusions and a low grade fever! something is depleting everything my s

This : This sounds like thrombocytopenic purpura. It can be caused by a variety of conditions, but sometimes there is no cause identified (in which case it's called idiopathic.) if she is not being seen by a hematologist, she definitely should be. Has she been exposed to heparin? This is a common intravenous or subcutaneous medication that can cause a similar picture in patients who are sensitive to it.

ITP: Some type of ITP or TTP would be of strong consideration. I hope you are in consult with a hematologist.