How to be composed and clearly talk about what's on your mind?

I have barrier issues at times, specially speaking english. As I’m quite slow in composing my mind when there’s this english barrier. Do you think, practicing the language everyday, would help me?

Also without even speaking english, just by speaking in my native tongue, I find it hard to say in words whats in the back of my mind. But I’m a good writer. I can compose through writing because there’s a time alloted. I also can compose through text and chat. I can also talk fast and looked composed through phone call. Why is that when in personal, people thought I’m shy and I could not speak up, but if they just know, I’m quite a talkative person inside. I just can’t express it.