Why do i stutter so much but only when i speak another language??

Why do i stutter so much but only when i speak another language?? So i can speak fairly well without stuttering in my native language and in english but the moment i speak in the language that i live in (Germany) i start stuttering A LOT. So much to the point i dont even say stuff anymore when i know im gonna stutter.. this only has started happening like almost a year ago and it got worse over time.. and its so annoying when my friend constantly says ‘just stop stuttering” as it i can just automatically stop that.. idk what to do about it i constantly stress about if i will stutter or not when talking to friends or even worse with strangers.. any help maybe??