Wayward

[Achebe]

The route, painstakingly penned from my own hand, ....'penned by' sounds more appropriate. 'Painstakingly penned' sounds terrible. why not just 'mapped by my own hand'? If you say 'penned', then the 'route' refers to a map of the route. The next line doesn't make sense after that.
stalls before me now, lost to the humors of fate. ...see above for 'map stalling'. what are the 'humours of fate'? are you referring to the Aristotelian humors of choler / melancholy / bile etc.? Or is it just fate being humorous? Sounds like a malapropism to me.
Once crisp and clear, it is given way. ...'crisp and clear' is cliched.
It looms, all vapor and mist, an entity in itself before me. ...dale has already touched upon 'too many Its'. The route is an entity? Meaning that it has a defined, independent, existence? isn't that always the case? Or do you mean a living entity? 

Yet in it I have found a space.  
I am free to inhale its milky breath,  
the heaviness of it weighing on my lungs.
I wait for consciousness to fade, to absorb into the gray. is it milky, or gray?

But it does not. It will not.
Instead of screaming to leave, I am drawn to stay. Why would you scream to leave? you're just standing in the mist. You have, in fact, found in the mist-beast's entrails a "space". The 'instead' is out of place.
My self is speaking now and it is not afraid, your 'self' is you, isn't it? why even mention it? unless your 'self' is some sort of inner consciousness that is saying things that you normally wouldn't - but nothing in the rest of the poem suggests anything like that.
it has uncovered an engaging apathy.

I will take it up, this fog.
I will let it lay in my hair, against my skin.
I will soften my edges until it pours into me.
There is no need to flow forward, to push on.

I am here, in this mist,
and I am brighter than I have ever been. Why? what has the mist done to you? If you had a mystical experience standing in the mist, then that could be the key point of the poem. As it stands, I am not sure why an everyday experience has made you brighter than ever before, and now I want my money back.