روابط در لاراول

سلام
میشه توی لاراول،یک موجودیت زیر مجموعه یک موجودیت دیگه باشه و از طرفی خودش زیر مجموعه داشته باشه
مثلا یک کتگوری ،چند تا زیر کتگوری داشته باشه و هر زیرکتگوری، چند تا پست داشته باشه
من اینو پیاده سازی کردم ولی ارور میده

Products.php:

<?php

namespace App\Models;
use Illuminate\Support\Facades\Storage;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    use HasFactory;
    protected $fillable=['title','content','image','mymodel_id','warehouse_id',];

            public function deleteImage(){
                Storage::delete($this->image);
            }

            //blongs to a -model- and -warehouse-

            public function warehouse(){
                return $this->belongsTo(Warehouse::class);
            }

            public function mymodel(){
                return $this->belongsTo(MyModel::class);
            }
}

Category.php:

<?php

namespace App\Models;
use Illuminate\Support\Facades\Storage;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Category extends Model
{
    use HasFactory;
    protected $fillable=['name','description','image'];
    //has many models
    public function mymodels(){
        return $this->hasMany(MyModel::class);
    }

    public function deleteImage(){
        Storage::delete($this->image);
    }

}

MyModel.php:

<?php

namespace App\Models;
use Illuminate\Support\Facades\Storage;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class MyModel extends Model
{
    use HasFactory;
    protected $fillable=['name','description','image','category_id'];

            public function deleteImage(){
                Storage::delete($this->image);
            }
            public function category(){
                return $this->belongsTo(Category::class);
            }

            public function products(){
                return $this->hasMany(Product::class);
            }
}