O.S.
If you think your idea is patentable don't show it to anyone until you have talked to a lawyer and take the steps to patent it. If you need something done do it yourself or if you need help make the person sign a confidentiality agreement, you don't need a layer for this typically when you agree to something in writing it is legally binding. Open Innovation is big word now a days with big companies in which they source ideas from people like you, however they will be hesitant to sign confidentiality agreements for many good reasons, so if you plan to pitch your idea to someone again make sure you have it protected from the patentability standpoint if you can't then make sure you document who you are meeting with their role and that you document the outcome of the meeting all this is also legally binding if documented properly. Take a pic of your invention and put it in a notebook and have a witness sign it, and date it. This could be your neighbor, spouse, cousin, etc however let it be someone you can trust. All of this certifies the ideas as yours, make a copy of the page and mail it to yourself and don't open once you receive it just save it. This will state that all dates are correct and real and will establish a timeline in case you need it. Sorry I can't help with how to commercialize it but I hope the information as to how to protect your ideas are helpful.
O.