Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by the bruise on your back for the last 2 years along with joint pains, kidney pain, chest pain, fatigue, insomnia and recently hair loss.
Hair loss may occur as part of an underlying disease, such as lupus or diabetes. Since hair loss may be an early sign of a disease, it is important to find the cause so that it can be treated. Lupus also follows the pattern of disease symptoms interspersed with disease free period when no symptoms are present. If on the basis of these symptoms, lupus is suspected you must go for ANA test, complete blood count, urinalysis to look for protein. Bruise also need to be seen by a dermatologist if it is some form of rash and its true nature.
As it is not possible to make diagnosis online, you must visit your doctor for the same.
Hope this helps. Take care.