I cannot help but feel irritated that nobody seems to understand me…

I cannot help but feel irritated that nobody seems to understand me… It feels as if every time I speak to strangers they do not understand what I have said. They just say something like “sorry what” or any ruder or more polite variation on this. I already feel so exhausted by speaking that having to then repeat myself AGAIN drives me truly mad. Often, I will repeat it, with even less fluency and more uncertainty than my first attempt, and then they still do not understand. On multiple occasions today, I gave up and found myself reducing my requests down to a single word until they understood me. It is so degrading. I do not know whether what I say is truly unintelligible or if people just hear me stammering and do not even try to listen. In all honestly, this constant feature of my day-to-day life whenever I speak to anybody makes me feel so depressed and irritated. I find it very difficult to steel myself and speak to people, especially strangers and in public, so to do so only for it to then be incomprehensible is awful. I do not even know what to do about it: I always feel so frustrated in the moment and then linger on the shame it brought me for a long time after. What should I do: is it me or is it just that people do not care to listen to me? Should I just not bother to speak anymore?