If you are having neck, shoulder, and back pain, it is important to seek medical treatment right away and explain your symptoms to the doctor and the cause of your pain. Also, you should contact an experienced attorney in your area to make sure your rights are being protected and to help you with the insurance company.
I will preface this by stating that the laws in your area are most likely different from those which I practice under. Therefore, I should tell you that I am unfamiliar with those laws.
Nevertheless, my recommendation remains the same, speak to an attorney in your area. The benefits of doing this are plenty. One of the main principles of law is to protect your client's rights. I would not recommend you speak to the insurance company until you get the advice of local counsel. You can go through your local State Bar and get names of attorneys that practice Personal Injury. The insurance company may want a recorded statement. Again, I would not advise my client to give one, but you should confirm with a local attorney with knowledge in this field. They should be able to ask questions to help get the details they need.
I strongly recommend you contact an attorney to discuss this matter in further detail, so as to allow you to get more accurate advice, and to do so without haste.
The most important concern is your health - seek immediate medical attention for your injuries. When you first see a doctor, be sure to explain that you were injured in an auto accident. If you do not have health insurance, some doctors are willing to treat you regardless because your injuries are from a motor vehicle accident.
The next step would be to contact an experienced personal injury attorney. It is not advisable for you to speak with the other driver's insurance company without first speaking with an attorney.
You should obtain needed medical care and treatment immediately and follow your doctor's advice. Do not give any statement to the adverse party or insurance company. Do not grant them access to your medical records. Photograph your injuries and the damage done to any vehicle or other property. Contact a personal injury attorney in your area as soon as possible so that you can protect your rights.
You may also find it helpful to review the Legal Guides I have published on Avvo.com dealing with many of the issues you are now facing.
You should not give a statement to the insurance company until at least speaking with an attorney. Second, if you have not sought medical attention, you should do so immediately to make sure that your injuries are not life-threatening.
If you choose to handle this claim on your own, you should consider whether your health insurance will demand its money back, whether you have medical payments coverage on your own insurance to pay your medical bills, and whether you are entitled to a rental car while your car is being repaired. There are so many different things for you to consider and do that it is impossible to list them all here