What should i do to make him feel better?

The guy I'm dating is going to be deployed in Afghanistan in March. He is in the army and he is depressed and stressed. I wanna make his feel better but i don't know what to do. I always tell him that I'm here for him but i know that doesn't help much. He tells me that he is just gonna give up on life because he doesn't know if he'll come home alive. It saddens me whenever he feels like that. I also developed strong feelings for him since we have been dating for 4 months but i am holding back because i know he has a lot going on and i don't wanna add up to whatever it is that is stressing him out. How do i make him feel better?