I was at the same situation last year. I'm Brazilian and went in an exchange to Portugal. Although is the same language, I connected more with people from other countries (like Germany and italy) so I was required to speak English to talk to them. In the beginning was a bit harder and I was stuttering more than in my native language. As the time went on I figured the, since I have to think I bit more about what I'm gonna say, to check for any language mistakes, I could anticipate any possible blocks I might have and change my breath to make the chances of that block happening smaller; or even try to find a substitute to that word.