Pushing Myself to not take "no" for an answer

In the first week of research, I immediately learned that my approach was not working for our participants. The number of participants drops as days go by, and I don't get feedback from them. I knew something was not right, so I changed my approach. It is good that I am building it without code, so I can make change to the product quickly. However, I have already lost many participants who are willing to test it for me. Now what?

"My product" relies on emails, and I send many emails to participants. I decided to use it to try again. I added an "unsubscribe" feature in my next email. When they want to "unsubscribe", they go through a form to give feedback. In addition, I re-emphasized that I want the product to work for them, and it is entirely free during the research. The product costs $60/week - I have to pay for the service they receive during the research. I highlight that they are missing out on the opportunities to use this free service if they decide to cancel. If they are still interested in taking advantage of the product, they can schedule a call with me to see how they can get the most out of the product.

I am not sure if this will work. People can simply ignore and delete the email. In the last couple of days, I keep thinking I should give up on people who decide to leave - I know I don't have the solution that is working, but I know I am solving a problem they want to solve. After thinking through this, I decided to break my old habit of "taking no for an answer" by trying not to take "no" for an answer.

What'll happen? I don't know, but I am excited to find out!