Is it worrying & difficult to have an English conversation for non-native speakers?

It depends. Non-native English speakers who've been learn & practicing English might be able to talk with native English speakers without a lot of difficulty because they are used to English a lot or slightly.
For many non-native English speakers including me, it's tough a bit or a lot to speak English naturally as well as they can. However, I don't  believe it's impossible, if non-native speakers continue learning & practicing English & get used to it.
In this article, I'm going to share with you a video from YouTube. Here's the video.

On the video, a non-native English speaker girl's talking with a native English speaker guy. According the video, the girl is native Chinese speaker. It seems to me that the girl's speaking English smoothly & naturally (although I'm not quite sure if her English is grammatically correct).

In my opinion, this video shows that non-native English speakers could speak English some day if they continue English & get used to it. This video is exciting & inspiring to me!

Anyway, that's it for the article. Thanks for your time & reading. Until next time, goodbye.