I think its best to paste some code, i.e, the code (theoretically) meeting your requirements that failed, and code that compiled and got the closest to meeting your requirements.
You don't actually have to instantiate the type for a receiver function (i.e., method). There's too much missing from your code for me to understand which direction you're going but you'll likely have to use a constraint for structs which is explained here: https://github.com/akutz/go-generics-the-hard-way/blob/main/...
Hopefully someone can bridge that gap for you.