Hello and thanks for writing. I can understand your concern and would try to help you in the best possible way. The problems you are facing could be summarised as having palpitations, neuropathy, shortness of breath and fatigue. These can be due to diabetes, heart conditions, anemia, vitamin B12 deficiency or anxiety disorder or any other cause. I suggest you get yourself worked up for the same. You may need to answer a few questions pertaining to your problems to help understand the nature of your illness. You may also require a complete physical examination including some tests like complete blood count, peripheral smear, fasting glucose levels, vitamin b12 levels and other tests. Once a diagnosis is made a comprehensive management plan may be started for you which may include dietary advices, lifestyle modifications, medication and physical therapy.