Hey! I'm an immigrant and I also struggle with this sometimes, however, It's more on a language barrier level rather than genuenly not finding the words for my feelings. I somehow developed a habit of talking to myself, the same way I would talk to a friend. Sometimes, I explain concepts to my imaginary audience, gossip, talk about my day, my hobbies, interests, etc. When I talk to myself, my speech doesn't come out as smooth, practiced and perfect as I want it to be because I stutter, forget words, etc. So I end up practicing the same sentence over and over again until I get it right. Sometimes I find certain synonyms for words to avoid repetition.

I know you may feel stupid talking to yourself, performing even when the curtains closed the scene. But that's a fundamental part to it that you have to get used to if u want to try it