I’ve studied it off and on since high school, but really struggle with speak. I get anxious about the times and accidentally saying something nonsensical. But we had a family show up that didn’t speak English, and I was able to do more than crank out 谢谢。
I have a feeling 我（的）中文不好 is too much of a statement of fact to work here, but I’m not good enough at Chinese to provide a good alternative. Maybe a simple 还不好啊 would make more sense? I’m not sure, but “when in doubt, put 啊” seems to generally be a good rule of thumb in Chinese.
I would personally say 我(的)中文還不怎麼好啦/我的中文还不怎么好啦 (wǒ de zhōngwén hái bùzěnme* hǎo la). 啦 carries a bit of humbleness and is often used when denying a praise. 啊 wouldn’t really work here, though I can’t really tell you why. Might be because it can (depending on tone) sound like you’re denying sth impatiently and that it should be obvious, I think? … sorry I don’t really know how to put this into words precisely.
*Although 怎麼/么 is usually said to be pronounced as zěnme, I have always felt it’s more aptly described as zeme.
That makes a lot of sense, thanks for the tip.