I have tried what you are attempting. Same thing will likely happen. You will run into the attitude that if the idea has any merit they would have thought of it. At least you have a patent.
Your best bet, partner with a good lawyer ( otherwise you won't be able to afford the subsequent legal costs ). Send proposals to lots of companies. If you idea is really useful and can be made profitable then sooner or later someone will put it into a product, forgetting where the idea came from. File your lawsuit(s) and set back and get rich.
I have people come to me with idea for products many times in the last 20 years. They are always concerned someone is going to "steal" their idea. I tell the all the same thing, if your idea is any good you won't have to worry about them stealing it, you will have to ram it down their throats.