Authentic Mexican Shrimp Cocktail (Coctel de Camarones estilo Mexicano)

Name: Authentic Mexican Shrimp Cocktail (Coctel de Camarones estilo Mexicano)
Prep time: 45 min
Total time: 45 min
Cuisine: Mexican
Ingredients: 0.33333334326744 cup Spanish onion, chopped; 0.25 cup freshly squeezed lime juice; 1 pound chilled cooked medium shrimp - peeled, deveined, and tails removed; 2 roma (plum) tomatoes, chopped; 1 cucumber, finely chopped; 1 stalk celery, finely chopped; 1 jalapeno pepper, seeded and finely chopped; 2 teaspoons salt; 2 teaspoons ground black pepper; 1.5 cups chilled tomato and clam juice cocktail (such as Clamato®); 1 cup chilled ketchup (such as Heinz®); 1 bunch fresh cilantro - stems discarded and leaves chopped; 2 tablespoons hot pepper sauce (such as Valentina®); 2 avocados - peeled, pitted, and chopped