A few things,
@OnlyIn does literally nothing for modders, it's only supposed to be used internally in Minecraft, use
@Mod.EventBusSubscriber(modid = "exampleid", value = Dist.CLIENT)
to ensure it's only called on the client, not that you have to use static methods with EventBusSubscriber, and instead of registering an instance of your class you register the class object directly. See the image I attached for more info.
You should also not use the raw RenderGameOverlayEvent, I recommend RenderGameOverlayEvent#Post.
For mods you should always use ElementType.ALL to distinguish from vanilla and you should rebind the default GUI textures after you're finished with you're rendering