1. Put Your Situation In Perspective. Realize that the worst thing in this process has already happened to you - you have been terminated. The employer can't really take away anything more from you than they already have - your job and your income.
2. Keep in mind that your case is a civil case (as opposed to criminal). No matter what happen in your case - neither you nor your former managers will go to jail, and your case will generally revolve around whether or not it can be settled or whether it will go to trial or arbitration. Some cases are dismissed by court due to lack of evidence, and that's an inherent risk of employment litigation. Your attorney should evaluate your case in great detail before deciding to pursue it in order to minimize the risk of your case being dismissed.
3. Work with the right lawyer. Work with a lawyer who you are comfortable with, i.e. somehow who strikes you as knowledgeable, personable, responsive, and who you can ask to explain not only what your course of action in your case will be but also why. Often that will not be the same lawyer who has the sharpest website or the largest billboard on a highway, or someone who is too sure of himself. Be sure to share with your lawyer your biggest concerns about your potential case, so that he can address them and help you make the right decision and what your next steps should be.