Cloudy Days

My first try at writing an iambic pentameter poem. I just want some advice and "constructive criticism." Just some tips on grammar, form, wording, etc. Anything helps.

Should you believe me on a cloudy day,

Instead a lucid sky and Sun it's king,

When drunken jargon is the most I say,

And lover's heartache thus begins to sing.

 

Then was the light when we're together;

Now born a fool amid the cold weather,

And most of our fortunes have fled off trail,

In search for a lost cause to no avail.