I’m 17 and went to speech therapy for 7 years. One of the biggest aspects of stuttering for me is my confidence. Something that helped me to not get stuck on certain phrases or words more then once is that once you get stuck you stop trying to say the word (only while alone not in normal conversation) then you say it again but this time stuttering on purpose. Then you use breathing strategies to very calmly and confidently say the word or phrase. This helps to remove any mental block over certain words or phrases.