Hi, Welcome to HCM. I understand your frustration and concern about your deteriorating health. Lyme disease as such occurs in three stages. First stage is just a rash at the site of tick bite. This disease is caused by bacteria called borrelia which survives in gut of ticks. Second stage presents with fever, headache, joint pains, body pains and swelling of nodes. Third stage is the chronic stage where the patient is having joint pains, fatigue and dermatitis. You are suffering from the third stage where generalized weakness will be present. Diagnosis of Lymes disease is difficult because the bacteria causing it does not grow so easily and isolation is difficult. Also antibodies against this bacteria is produced late (almost 1-2 months), so difficult to diagnose by lab tests too. Doxycycline is the drug of choice for this infection. I suggest you get in touch with your doctor for change of antibiotics as you are not responding to Doxycycline. Cephalosporins are useful to control this infection. Also you have to understand that age plays an important role. I suggest good healthy diet to boost your immune system. I hope I have helped you. Wishing you a speedy recovery. Thanks.