This world is hard, this world is cold, this world is agony

How can I maintain an ordinary life, wife and maybe kids, job and all that comes with, house and more bills, etc whilst keeping on a permanent mask to keep all and sundry hidden from my deepest black? This damned depression that won't go away and is now pretty much a part of me, is me, for good or for ill?
How can I even contemplate a relationship with someone ever again and not fear them leaving because they can't cope? What hope do I have of having someone to love and trust? Who'd want me with this?
I walked back to the station in a daze, tears pushing hard, thoughts emotional, playing through my lack of coping ability to do small things lately, playing through jumping in the river that marks my walk to and from the station- how would it go, would I panic? Would I let it envelope me, would I sink or fight it and swim? What would I do?
I'm tired of my own thoughts and I'm tired of this depression and having each day be a fight, a battle in a war that is never-ending and is always raging. 
The only real way out would be a  victory.
A Pyrrhic one.