Reminds me of when I was in Germany and I was studying German.  I threw the grammar rules out the window and I just talked.  It helped a lot.  You should study grammar later but don't worry too much while you're speaking.

Hey, I completely agree with you. The best way to learn the language is to be a 'child' as you stated. It a matter of practice without being ashamed. However sometimes is hard to accomplish it, specially when one is surrounded by other people who look at you with a wierd face when you try to practice the pronunciation xD

i think someone will fear this problem but if you overcome it , you will succeed :)

because if you do not have the words, you will not speak, read, write, hear. I'm not saying that grammar is not important but most important vocabulary to communicate

Being a child is recommended in a number of books I have read on how to learn a language more efficiently. So I would suggest that you look for American cartoons for kids on YouTube to watch. The vocabulary will be easier to follow because the show is targeted towards children. The grammar will also be easier. Use that for listening practice. Also, go on Ebay, Amazon, or another site and buy childrens books and comic books to read. Comic books will be good in a way too because you will learn conversational English from them as mostly speech bubbles appear in comic books. The drawings will aid you in the context that something is being said too. Vocabulary is important but so is grammar. No one is going to understand you if you rattle off a bunch of vocabulary words while having crappy grammar. Hehehe So do not slack on studying grammar too.