Are We Different People in Different Languages?
Yes, to the extent of "different".
Native languages parse through the emotional center of our brains whille non-native ones parse through the reasoning part. This makes decision-making in different in non-native language; it's also the reason you read a speech in the listeners' native language if you want to have a higher chance of them agreeing with you.
Personally, I find myself more reasonable and critically thinking when speaking in English (which includes internal dialogue). I'm able to push through emotionally-stressful situations easier when conversing about them in English. It doesn't change my perception of what is emotionally stressful; I guess it parses the situation slightly differently.