Wolfox is depressed because he is simply a selfish arsehole. Some people just lack character and are shallow human beings and don't recognise it. These people don't deserve happiness. Wolfox is getting exactly what he deserves. (Ratard also).
My advice, practice some self reflection and develop the ability to become MORE aware of yourself, you will find you are a massive unlikable arsehole (your own unconscious self despises you, although you remain unaware of it) and this has greatly contributed to your misery. Finding out who you are, even if that means learning your a massive prick will bring some relief. Hope this helps