I just completed my Software Engineering degree yesterday. During my university, I also used to give presentations infront of the whole class. Some went decent but some went so bad and horrible to an extent that I was in depression for many days and It greatly impacted my self esteem and confidence. I think that everyone experiences ups and downs in stammering and there is no regular pattern and thats why I think that its very difficult to master public speeches. But I'll definitely look into the resources you provided. Also, I wish you best of luck for your career as speech therapist.