Unfortunately, when you apply for social security disability, you have to essentially prove to SSA you are disabled with objective medical evidence and treating source statements. The more evidence you have, the more SSA will believe you. Consequently, it is a good idea to have all your ducks in a row before you even apply.
For instance, when you initially apply, before SSA can make a decision, they have one of their medical consultants fill out what is called a residual functioning capacity form. This form is filled out by a doctor who has never examined you --- they fill it out by the medical records alone. However, if you have your doctor fill it out instead, they have to give it more weight because he or she is an examining, treating physician. Consequently, if you haven't turned in one from your doctor yet, try to get him or her to fill one out for you and turn it in to SSA. If you google residual functioning capacity form, you will find a blank form to take into your doctor.
Secondly, if you're under 50 years of age, it is even harder to get approved for disability whereas after 50, some of the standards are lessened. My advice to you is --- when you see your doctor, make sure you tell him or her all your symptoms. Secondly, if you're struggling with any kind of depression, see a mental health counselor. If you're experiecing pain, see a pain management doctor. Every bit of medical evidence you have can make a difference. Hope that helps some.