Was I wrongfully terminated? What should I do?

During the course of my employment a new supervisor was hired. She was still training during my 1 year review, which went excellent and had no negative marks on it. Shortly after her training was finished oddly enough she quickly named me “Rule breaker.” Offensive yes, demeaning and just not how a supervisor should treat employees. She fired me 2 months after my review for not coming to work 10 minutes early. I requested my employee file that shows several supposed “counseling” sessions that did not happen so she is guilty of false documentation. The employee handbook states it is “preferred to come 10 minutes early” but doesn’t say required. Handbook also has a sequence for discipline that she did not follow before termination. Do I have a case? Where do I start?? Please help, I feel so wronged.