Warm large pot over medium-high heat, then add butter. Once butter is melted, add celery and white parts of green onions. Cook until vegetables are tender, approximately 3 minutes.

Add garlic, salt, and black pepper. Stir well then cook 1 additional minute or until garlic is fragrant.

Sprinkle all-purpose flour into pot, stirring to coat vegetables. When vegetables are well-coated, remove pot from heat and pour in milk and heavy whipping cream. Return pot to heat, increase temperature to high, and bring mixture to boil while stirring constantly. Once liquid begins to boil, reduce heat and let simmer.

Add cream-style corn and corn kernels. Stir to distribute, then simmer approximately 5 minutes or until soup has thickened.

Add shrimp and Old Bay seasoning to thickened soup. Stir well and cook until shrimp is cooked-through and no longer translucent, approximately 3 minutes. Taste soup and adjust seasonings as desired. When ready, portion soup into serving bowls, garnish with green parts of green onions, and serve warm with warm bread if desired.