Educate yourself on divorce law in your state. Learn as much as you can online and discuss it with your attorney. Take a financial inventory of your assets and liabilities. If you do not know anything about finances because your spouse took care of that during the marriage, contact a Certified Financial Planner (CFP) or other financial specialist who can educate and help you in decisions on whether to keep the house, etc. They can also educate you on insurance and retirement accounts among other things.
Take Care of Your Mental Health Professionally
Seek out therapy to deal with the death of the marriage. You will have a difficult time getting divorced if you have not fully dealt with these issues. I do not believe that any individual can successfully get through a divorce without some sort of mental health therapy. It does not matter how "tough" you consider yourself.
Take your mind off the case
Build a support group. Get involved in new things to take the focus off your divorce. If you feel ready, start dating to get your mind off your ex. Go back to school. Get a job. Just do something. A divorce will consume you if you don't have something to take your mind off it.
Listen to and Take Advice
Most individuals going through a divorce have an attorney representing them. Communicate with your attorney and do what they tell/ask you to do. You will likely find that things will work out better for you if you do. Since your attorney 1) knows the law, 2) is not dealing emotional issues and 3) has been through many divorce cases, they probably have good ideas and better judgment than under the circumstances. If you cannot communicate with your attorney you should get a new one. Your attorney is supposed to help decrease the stress of a case and not add to it. It is easy to change attorneys--just go hire someone else. Your new attorney will fire your old one (one more stressful thing you will not have to deal with) .