Shrimp Enchiladas

butter, divided

medium-size shrimp, peeled and deveined

red bell pepper, diced

onion, diced

oregano

salt

garlic powder

cayenne pepper

all-purpose flour

heavy cream or half-and-half

sour cream

shredded cheese (such as Monterey Jack, Pepper Jack, etc.), divided

tomatoes, seeded and diced

(8-inch) flour tortillas