fired for no real reason

I worked for a company for 11 years, and lately my supervisor has been riding me on minor clerical errors. She made up a bogus probation the last month of my employment there and has been watching every move of mine to find a reason to fire me. The company has been laying off people left and right and giving them severence. I believe i was fired instead of laid off to save the company money. If i was fired for something agregios then why didn't they contest my unemployment insurance. My position which requires alot of knowledge of our company has been posted for an outside person to apply for. It would take someone at least 4 years to obtain the knowledge i had with the company. I believe my boss had a personal thing against me or her boss did. (The new VP of Sales) I'm gay, but have no proof that's what it was.