How do I stop getting stressed dealing with car insurance after wreck?

I am having to phone AllState again and again after I was in a car wreck, as they said they would pay for the car damage but they keep trying to avoid paying. I am getting so stressed by the phone calls – and I was injured so the whole thing is a real pain in the neck (feeble attempt at joke…). How can I reduce the stress (don't say massage or yoga please!!!!!). Should I get an attorney? Or is there some way to be firm but polite on the phone while I ask for what is rightfully due (from what I have heard about car insurance after a wreck). Any clues how to deal with the evil insurance adjuster on the end of the phone? This is really upsetting me, and it was bad enough being in the wreck.