How Can Neck And Body Soreness With Pressure Headaches Be Treated?

My car was rear ended 2 days ago. When I woke up yesterday, I experienced some neck and upper body soreness. Through out the day, I could feel it on my lower back as well but not at severe. As the day went, I felt more comfortable laying down. The discomfort and soreness increased this morning and felt some pressure headache at the bottom near my neck. Should I wait to see if it gets better or see a doctor immediately. Currently taking prescription strenght ibuprofen from previous ankle strength.