What did you feel when you read this sentence? I think the most important thing for you is to understand. In spite of the fact that there might be some mistakes but you tried to think and do your best to understand me.
If you find a mistake, I think you may laugh and feel happy and you may teach me how to do it the right way. This is how native English speakers feel.
Please, don't be shy while speaking with a different language. A mistake in a language is not like stealing or killing or telling a lie. It's a funny thing and it's a good opportunity to learn from others.
I'm not a native English speaker but I also teach my mother tongue language and I enjoy listening to the bad grammar and terrible vocabulary of learners lol :)
A non-native English speaker speaks slowly (unlike the native speakers) so it's normal to find it a little hard to understand native speakers and that's okay. That shouldn't make you feel shy.