Regardless of what anyone says, you must continue to believe in your ideas and yourself. You'll note my plural use of the word idea. More than one. I'm convinced that if you can come up with one new product idea, you'll undoubtedly have a hundred more behind that first one. Which is good since you'll need that many working at any one time in order to keep your sanity.
Overnight success takes about a year-or longer.
It's worth repeating. With enough of you out there mumbling that little thought often enough, we might create a proper mantra for inventors throughout the world. You can increase the odds of your success, by increasing the number of new product ideas you're working on at any given moment. Which means that if I live long enough about 4 or 5 of them little suckers should generate some income. I sincerely doubt it.