Yeah I think it definitely should be and yeah stammering affects a major part of life and this case it is being assessed so it should be taken seriously as a disability. I wouldn’t give up on it though push for it as it’s very important especially for your grade for the semesters. Thing that sucks is for English and Spanish in GCSE I had speaking exams and I got an F in both because of my stammer. I stated my disability and everything and still got nothing. Feel like stammering in general should be taken more seriously as it is such a major setback in life. Maybe you could try and push for some kind of equality act maybe or discrimination act? If they don’t accept “stammering” try and get the gp to reword as a speech disorder or something (which it absolutely is) would like to know the outcome of this as I’m intrigued 👍