why do I pause mid sentence while talking?

why do I pause mid sentence while talking? Ever since I was 9 I've had a major speech impairment where I'll pause mid sentence. It basically feels like the words are in my mind but just won't come out my mouth. It also happens a lot when I have to repeat what I said multiple times to someone. I found out that exaggerating my movements and slurring my words slightly helps with it but not by much. It'd pretty much go down like this, "Hey man did you hear about the-........... Thheeeeee new game that came out last week?". You can imagine how embarrassing this has been for me my entire life. TLDR: I pause/feel stuck on words mid sentence.