Its somewhere between depression and focus, in that we find it difficult to motivate, though also PTSD definately limits our concentration and memory when uncontrolled. These are facts, however; he either chooses to accept the way he is, or he gets off his arse and does something about his PTSD. Being male has a lot to do with some of the issue though.

Good to see atleast he is helping by cooking the evening meal. Now if you slowly get him more motivated over time, your issues will become less, thus the relationship itself improves slightly.