The symptoms you've described suggest that there's oral vitiligo that has a white spot inside your mouth, which can cause fever and weight loss and may also contribute to blood loss because of lung cancer. It's a good idea to set aside an appointment with a tumor specialist as soon as possible for proper diagnosis and treatment planning.
Doctor, you've got a fever, you've got a spasm in your elbow, you've lost your elbow, you're losing weight, you're vomiting blood, and what's the cause of these symptoms?