Speaking badly is a VASTLY more effective form of communication than not speaking at all. There’s a fair chance you can make yourself at least partly understood.
I spend part of my time at work doing inpatient phlebotomy. There’s a standard script you run through for this in order to let the patient know what’s going on and obtain consent, something like “Hi, my name is xplo, I’m from the lab, I need to draw some blood from you.”
Before I started studying Japanese again, I encountered an old Japanese woman with basically no English. Now, in theory, the hospital provides translation resources. But it involves calling people on the phone and is generally cumbersome and the kind of thing you use for making important medical decisions, not for doing a blood draw that normally takes a few minutes. Likewise, we don’t pull out a smartphone and start fiddling with it. With patients who are drugged, very sick, mentally incompetent, or non-English speaking, we just do our best. (The nurse can verify ID if necessary, but consent can be… hazy.)
I still remembered a bit from the first time I studied Japanese, 20 years ago, so I got her to say her name and birthday, for ID purposes, and to repeat her birthday when I didn’t catch it the first time (もう一度言いてください is a very handy phrase to know if you expect to speak Japanese when you’re pretty bad at it). But I didn’t really know how to tell her anything else. There are words for “hospital laboratory” (which is distinct from 研究室 which is a research lab, not a clinical testing lab) and “blood draw”, and I still don’t have them memorized.
But I like to run back that memory in my head. If I knew then what I know now, what might I have said? Right now, that script goes something like:
Is some of the grammar a bit off? I think so. Would she have understood when I meant by テーストすること研究室 or 血を引きます? I have no idea.
But this is the kind of stuff you need to do to improve after a certain point, I guess. Maybe better to do it with tutors or endlessly patient Japanese friends than with hospital patients… but my point is, just get some words out. Do your best. Give them some idea of what you’re trying to talk about. Maybe they’ll get it. Maybe they can meet you halfway: talk slower, use simpler language, explain more, code switch back and forth if they know a little English and there’s a word you just don’t know.
Also, if you’re talking to a Japanese native who doesn’t speak English, just a little bit of Japanese will stop them from doing that “oh god, I don’t know what they’re saying, I’ll just smile or pretend they don’t exist or something” bit. Even if your conversation is frustratingly awkward or unproductive, the fact that you can communicate at all will make them respond differently.