Dog diagnosed with stress colitis

My dog, about 1.5yFS, was diagnosed with stress colitis after being weird about her food and not eating last night and this morning. She got groomed on Saturday which is when she started being weird with her food. She also gets carsick and vomited in the car twice yesterday and once this morning. She’s drinking well but has not eaten. Dr sent us home with proviable, trazadone, another med I can’t remember the name of, and low fat prescription cards. I’m worried that it’s something bigger as I looked up stress colitis and it said dogs often retain their appetite. Am I overthinking this?