Dysthymia depression. Me. plz help me.

I'm unable to understand what kind of depression he has. Our counsellor told us he is going through depression, above mentioned depression. But he is absolutely fine outside home. He is going outings, parties, everything he is njoying. But when home it feels like he don't wanna be with me. N feels he don't want any responsibilities. I'm unable to understand. N also I'm in mental stress. I'm unable to eat, sleep, feels like taking up my life, don't know, he is smart enough to build that he has depression. So that he can get rid of all the responsibilities. He has lotttttttttt of pressure in office. He goes around by 2 in the afternoon n come back home at 6 in the morning. As they want to remove him from work. N he is being close to his female colleague to which is hurting me. Plz help me.