Saying “mouthwash” in general is not specific enough. There are lots of types of mouthwash. I personally always go for flouride and alcohol mouthwash, so it kills germs and provides protection for my teeth. If the alcohol is what’s hurting your mouth, use alcohol free anti-cavity (flouride) mouthwash. Maybe you’re using the gingivitis mouthwash? Or the alcohol mouthwash? It doesn’t make sense to say all mouthwash does the same thing to your mouth