Why do I have pain in my bones, listlessness and a short term memory?

It depends. This doesn't sound like any one obvious thing. Bone pain can come overuse, polymyalgia, or fibromyalgia. Listlessness can come from depression, anemia, of chronic fatigue syndrome. Short term memory loss can come from depression, distraction, stress, or dementia. It's probably worthwhile seeing a doctor who can spend the time to go through each of these symptoms and carry out a complete exam.