The symptoms of muscle loss, weakness and shaking hands can be symptomatic of various illness. Only a physician will be able to confirm the seriousness of your present feelings of illness.
If you do not have a primary care physician, then I would encourage you to visit a local clinic, or perhaps you could contact the physican' s office of a family member, or friend requesting to be seen by him or her. In the phone call you will be able to describe the symptoms you described in your question and any other pertinent information the nurse may request from you.
I would encourage you to go to an emergency room, if your symptoms worsen before a physician can see you. At times in the winter months especially, different viral infections cause us discomfort, but only a physician is qualified to diagnosis our symptoms and treat us appropriately.