Look, when I decided to get into modding C# was the only language I knew. I saw forge and minecraft, were programmed in Java, but I didn't want to learn Java because I loved C#. I looked everywhere for ways to do it and couldn't find none. it's a non-sensical task: you'd need to write wrappers for all the classes that minecraft and forge provides, and then you would need to keep updating it everytime a new mapping or forge/minecraft version came out. it's a lot of work, for very little benefit, the modding communnity isn't big enough for this to be a reasonable project.
you could look into how to write c# that compiles to jar's, sure.. but you still would need access to classes that exist in Java code.
What I can tell you is that it is not worth it. We, programmers, can't fall in love for a language and try do to everything with it, it's a very common programming sin. You need to recognize the best language for the job, and accept it. And if you just ahte the language so much you can't even think of writing in it, then maybe not doing the project is just a better option
The best I could recommend you, if you really don't want to write Java, is to take a look at Kotlin or Scala, they are better versions of Java basically.
Or do what I did, learned Java, it isn't even that bad. but having to do C programming really lowered my bars
and also, maybe think a little bit before saying a Forum Moderator that has been contributing to the modding community for 8+ years, doesn't know what he's talking about. you're the newbie here, tyring to do something that is, honestly, idiotic