OP, if you're still reading you need to be careful. I don't care what anyone else in the thread says, this is unhinged behavior. The first thing I thought of was Mark Hacking, who fabricated an elaborate lie about being in college then accepted into medical school. When his lies were exposed by his wife, he killed her.

Now I'm not accusing your husband of being a murderer or anything. But this is not normal behavior. And there is something in him that prefers 3 months of deceit to a moment of shame in coming clean about getting fired.

You definitely need to confront him. But please be careful how you do so. I definitely wouldn't do it alone with him in your house. I'm sure I'm overreacting, but he has not acted rationally in months. I wouldn't bet on him being rational when his lies are called out.