Expressing myself is difficult!!! or: It is difficult to express myself

How long does it take so that I can express myself well?

I have been wondering me about this question too much because I can't find the precise words to express myself, some times I have/got the idea that I want to express but always there is always something  that suddenly makes the words disappear.

This situation is very frustrating and (it) makes me feel like a little child when I trying to talk with someone in English, I hope you guys can help me, by giving me some advice to improve my conversation skills.

Thank you for reading to me!

 You can start by speaking to yourself... XD

Expressing myself is difficult!!!

How long does it take so that until I can express myself well?

I have been thinking about me this question too much because I can't find the right words to express myself, some times I have gotten the idea that I want to express but always there is something that suddenly makes the words disappear.

This situation is very frustrating and makes me feel like a little child when I'm trying to talk with someone in English. I hope you guys can help me, by giving me some advice to improve my conversation skills.

Thank you for reading! to me

First of all, be careful with that closing. When you say "reading to me" it means somebody else is reading, and you are listening.

As for your actual question: The best way to overcome forgetting all this vocabulary is simply to study and practice. After a while you will stop forgetting words. If it helps, classic study techniques such as flashcards may help, but it all needs to be tailored to the needs of the learner. 

I like Ellie's corrections.  I would like to add 2 things: 

Express myself is difficult!!!

How long does it take so that I can express myself well?

I have been wondering me this question to much<font style="background-color: yellow;">. </font><strike> because </strike> [new sentence] I can't find the precise words to express myself<font style="background-color: yellow;">.</font> [new sentence] , <font style="background-color: yellow;">Sometimes</font> I have got the idea that I want to express but always there is something that suddenly makes the words desappear.

This situation is very frustrating and makes me feel like a little child when I trying to talk with someone in English, I hope you guys can help me, giving me some advices to improve my conversation skills.

Thank you for reading to me!