I think it is a common, nearly universal, fault that we tend to overestimate the value of our ideas. Most ideas need considerable work to make them useful, practical, and valuable. But there are exceptions, and the fabled stories of those exceptions that fill the minds of most inventors.
There are also stories of inventors being foolish or being cheated out of their inventions. That too drives paranoia.
The cure to paranoia is to hire an experienced patent attorney. I suspect that money and mistrust are the obstacles to that. With my patents, I worked for big companies with patent attorneys on staff, so the process was easy. The US attorney told me that public disclosure triggers a one-year timer to make a patent application. That year gives you six months or so to drum up interest, before you decide to invest in a patent application.
In cases where you decide against filing an application, my former employer (ASEA in Sweden) published disclosures in tiny little newspapers in Lapland with circulation 5. The purpose was to poison the water for anyone else seeking to patent that thing, but hopefully not inspire competitors by reading your disclosure. In my experience, the ratio was about 10:1 for possibly patentable ideas, to those we actually wrote patent applications for.
There is also a practice of non-public disclosures. You write up the idea and show it to two colleagues who date and sign it. That establishes the date in case of future disputes about who was first.
I like the Euro patent rules better than the American ones. In Europe, you have to continue paying fees every year to maintain a patent once granted. There is no fee like that in America. The fee encourages inventors to either exploit the idea, or to abandon it and make it public. I think it is evil to gain a patent, then just sit on it until expiration. Drug companies do that all the time.
The whole justification for having a patent system is to motivate inventors to publicly disclose the ideas. The reward is a exclusive right to exploit it for a limited period of time. Inventions carried to the grave benefit no one.