Speaking is a torture

During conversations I hate it when I get lost for certain expressions and pause for some seconds, sometimes up to 10 seconds, to come up with them while the other person keeps silent and often looks at me strangely. I get mad when I see that some people try hard to suppress their mocking laughter. The moment of silence produced is a great shame and embarrassment for me.
I'm equally ashamed when I say something but then I immediately realize that the expressions I just used were inappropriate or they were wrong in a truly embarrassing way.
My listening, reading and writing are not much of a problem for me as speaking.

How can you transform into a clear and fluent speaker who speaks like a native speaker and easily expresses oneself?

Please give me practical advice, not just theoretical solutions that only "seem" to work.

Ð`st kip pràktysing ànd ýu mòst sert`nli wyl nòtys s`kses. Þe ònli waý tu ympruv ys ekstrim tràýning.

Just keep practising and you msot certainly will notice sucses. The only way to improve is extreme training.

Talk to yourself as much as you can...

<<How can you transform into a clear and fluent speaker who speaks like a native speaker and easily expresses oneself? >>

Practice, practice, practice. In my case, a decade or so of total immersion did the trick.