Why is it that I ‘practice’ saying something more by myself I end up getting scared of that word?

Why is it that I ‘practice’ saying something more by myself I end up getting scared of that word? Like if I stutter on something and I go home and practice saying the word out loud, it creates like a fear in my brain of the word.. so next time in a social situation, my brain refuses or like is reluctant on me saying that word. What can I do? What can I do if practicing saying the word makes things worse?