This isn’t legal advice, but here’s a tip for guys: if you find out you’re being lied to, consider changing your behavior to the point where she might leave you herself. It might sound funny, but for example, if you’re facing business losses and start looking unkempt, you might see her exit without you having to deal with the situation directly.
You’ll need proof that she lied about her age.
The laws aren’t very favorable for men in such cases, I’m sorry. So in your situation, it’s best to hire a lawyer as soon as possible.