So many times I have heard people say they can't speak English, when in fact they can speak it well enough. Why is that? I have since discovered that so many people feel insecure about speaking a second language if they are not fluent. Many think that if they are not fluent yet, they should not speak it at all. That is not true!
Learning a second language is a courageous and admirable thing to do. It takes a lot of dedication, discipline and practice. That is why no normal, decent person will ever laugh at or criticize someone who is speaking a language different from their native tongue, even if they are not fluent yet and might make mistakes. Anyone who does that is immature, ignorant and probably speaks only one language themselves!
The other reason why you absolutely should speak your second language, a lot, is because you need the practice! The more you practice the more you will learn and before you know it, you will be more fluent than you thought! It will help a tremendous amount to build your confidence and the more you speak it, the more you will get used to the things you thought were "hard", like maybe grammar. After a while, the "rules" you need to remember before you speak will become second nature and you will be much more comfortable.
I hope this has encouraged you to speak more and never be shy or ashamed of the fact that you are not quite fluent yet. I would always rather try and figure out what someone means if they are trying to talk to me so we can communicate, than just give up. After all, they are the one speaking a second language and they probably know much more English than what I know of their native language. I have even had encounters where it turned out to be a lot of fun because it involved silly hand gestures and hilarious sound effects! So there you go. Never be afraid to talk!