Speaking Fluency

I can easily start it., but find so hard to finish,,,

Everyone can speak well in their mother tongue. But what if they have to speak in a foreign language? Achieving speaking fluency in a foreign language like English is far from being simple. I studied English for so many years. I can start to talk in English so soon, and I am so enthusiastic of using my English, but it happens several times that I cannot end my speech as I am unable to find the right words in my sentences. It is so funny that I have a lot to say but I cannot remember the exact words in my memory, I wait for a moment to continue my sentence and keep thinking what words should have come from my mouths. 

Why this happens? One possible reason  is that  as a foreign language learner I have not enough speaking practices in my life. I was born in a country which regards English as a foreign language and thus I have very little opportunity to really use my English in speaking. It is really ironic that I rarely use my English in speaking after several years of learning it. Then, having friends speaking English  makes me so grateful for being able to speak English to communicate.