For the future, you should also contact you contact your campus disability office for an assessment. I don't know where you are from but most places these days have quite robust accommodation options. I was an immigrant, ESL student with a stutter in Canada and I wish I knew about this when I was at uni. I always got zero marks on my in class participation, sucked at my presentations and dealt with so much extra stress I did not have to. You can also see this as an opportunity to educate people and advocate for others who stutter, so this practice becomes more common! Don't feel embarrassed opening up to your professor or other university professionals, they have seen it all.