Is Inventhelp a legitimate company

When you send in your money to learn how to protect your invention, you get little but what you could have found at a local library, or a google search of "U.S. Patent Law".

If you truly have an invention, document everything, have it witnessed and notarized, then put all those papers in a safe deposit box somewhere that only you know about.

Then consult a patent attorney. Yes, he will cost a lot. "Is your invention worth it?" is a question only you can answer.