Irritated but not sore mouth. roof is yellow with red raised dots. no fever or cough. had tonsil stoned which just dislodged with new mouthwash. could this be because of mouthwash?

It's difficult to define the cause. If the new mouttwash is the culprit, the symptom should resolve after 6-8 hours with water gargling and eating. If symptom persists and you feel sick or have fever with sore throat, viral infection may be the cause. Whatever, you will have an answer within a day. If mouthwash is causing it, go back to the previous brand.

Probably not mouthwash, but discontinue mouthwash for a week nor so and see if irritation goes away. If irritation persists, see your Dentist. may be microbial infection. See your Dentist.