Unfortunately, you have not given sufficient details about yourself and about your complaint. For example, I don't know whether you smoke or have lost any weight. If you do have any additional complaints (e.g. loss of weight, breathlessness, diarrhoea, dizziness, etc.), then you should consult a competent doctor.
Referring to your question whether or not you should take any renerve remedies, I would say that all your requirements in vitamins, nutrients and essential factors will come from a balanced diet of cereal, chapattis, vegetables, fruit, pulses and meat (if you are a meat eater).
Vitamin tablets and tonics are no substitute for a healthy balanced diet. In addition, you will need a good exercise programme such as brisk walks in the evenings. Be sure to increase your exercises gradually. Your trembling and weakness may simply suggest that you are physically unfit and that you should gradually increase your physical activities.