[Steve sighs. He knows personally how hard it is not to think about the future. The idea of never seeing these people again. Even some that are from his world. Like Bucky...]

I know it is. But constantly thinking about won't make you feel any better. And it won't stop the inevitable from happening. [The inevitable in this case being them going home.] The best thing you can do is not let it effect your time here. Don't let it make you miserable.