Spray a slow cooker with nonstick cooking spray. Place pork in the bottom of the slow cooker. In a large mixing bowl, whisk together Diet Dr. Pepper, water, salt, pepper, garlic salt, diced green chiles, Truvia and enchilada sauce; pour over pork. Cover and cook on low for 8-10 hours.
Meanwhile, make chips by preheating the oven to 350 degrees F. Cut each tortilla into 8 pieces and place in an even layer on a large baking sheet (or two) lined with parchment paper. Generously spray cut tortillas with nonstick cooking spray and season with salt, as desired. Bake for 8 minutes, rotate the pan and bake for an additional 8-10 minutes or until chips are crisp. Let cool completely.
Shred pork in the slow cooker when it is done cooking. Preheat oven to 400 degrees F. Spread chips in an even layer on baking sheet. Top with pork, shredded cheese, corn, black beans and jalapeños. Bake for 5-10 minutes or until cheese has melted.
Remove from oven. Spoon sour cream into a Ziploc bag, clip the corner of the bag and drizzle over nachos. Top with pico and cilantro before serving.