You are NOT alone. This is such a common stage in the journey of inventing.
I can not speak to the validity of your invention, but here are a few thoughts.
1. If it is at all possible to gather more feedback from prospective customers, I would do that immediately. One of the possibilities might be to give them to a local sushi restaurant in exchange for the feedback from a test. This was not something you could have done before being patent pending. If you only have the prototype I saw on your website, maybe you could strike a deal with the restaurant to sit outside their door and do a survey. That kind of study will not only help you sell/license the patent rights, but it will ignite your fire again

2. I have a saying, "fail forward". That means don't let failure be the end of the road, just part of the process of success.
Remember, you will hear "no's" along the way to success. The people who become successful are not people that never heard a "no", but people who didn't stop until they got a yes!
Happy Inventing!
Lisa Lloyd