People are reselling my digital products without permission. Should I quit or is there a solution?

I create and sell app templates on platforms like CodeCanyon. I have released over 5 digital products so far.

Recently, I found that some websites are reselling my templates without permission. They are pricing them much lower than my original price, and this is affecting my sales.

When I tried to contact them or file a DMCA complaint, they either ignored it or sent me threatening messages. Some even said they would upload all my products to free download forums if I keep trying to take action.

I also submitted phishing reports to Google and contacted Envato, but I have not received any helpful response.

Now I am thinking about quitting this space. It feels like I have no control over my own work, and nothing stops these people from stealing and reselling it.

My questions are:

• Has anyone here dealt with this kind of issue?
• Is there any way to stop or block these websites?
• Are there better strategies or tools to protect digital products?
• Or is it better to stop selling templates altogether?

I have proof and a list of sites that are stealing my digital products and not just mine. Can I list all these digital product reselling and piracy sites here? Is there any way to stop them?