SO stressed and ignoring me? Help me... What do I do?

My SO is in the military and stressed with certain circumstances that he is involved in. Because he is stressed he has totally withdrawn from me - his one support system - and only plays video games all day and completely ignores me... 
Before we use to be so spontaneous and fun together and because of his stress he has completely withdrawn. I don't know what to do. I just feel so helpless.