Dear ceira: Fatigue can vary widely from person to person. Some say it can last a year or even more. It is unlikely that the pain you are experience is lymphedema. Lymphedema is a swelling that usually begins in the hand and can eventually lead to the entire arm. If the pain you have is not relieve, you should contact your doctor to assist you in determining the cause and identifying appropriate treatment. Information about lymphedema can be found on Dr. Susan Love's web site http://susanlovemd.com/community/questions/q030223.htm
lymphedema means there is swelling, related to lymph fluid building up. So, you can't call it lymphedema unless there's swelling. Elbow pain could be many things, including nerve irritation; but it's not a sign of lymphedema unless there's swelling. Back pain would not be due to lymphedema. In the context of breast cancer, one might wonder about tumor in the bones, and it's certainly something you need to report to your doctors; depending on circumstances, it might be chosen to check it with bone scan, CT scan, etc.
one source of info: www.lymphnet.org
you can find lots more if you search "lymphedema" in google, or your favorite search engine