I am someone who empathises with your situation.

However, look at it this way.

If it is such a great idea, chances are other people have already thought about it. To assume that you are the only person to have thought about something is just selfish and egotistical. Noone should have a monopoly on ideas.

If you were the only one with that idea, I'd say 80% of the time, it wasn't such a good idea in the first place.

If someone thought your idea was worth stealing, then I'd say that you should feel confident that your idea is a good one, steam ahead and speed to market.