Whole lips swollen/bad, gums red; is it ulcer + gum inflammation, stomatitis, or granuloma? Can’t tell, photo hard.

From the photo, the cat’s lips are red, thickened, and ulcerated, suggesting stomatitis. But stomatitis has many causes: mechanical injury, nutrient deficiency, bacteria, virus, autoimmune disease, dental disease.

For correct treatment, take the cat to a vet to find the specific cause.