Looking specifically for help with formatting and line breaks, but all critique is welcome!

I appreciated the way the length of your lines varied at the beginning. The one-word lines played nicely with the longer ones, and created a good cadence, I think. 

Also, I think that you broke up the sentences appropriately with line breaks. Had the lines been any longer, it may have become difficult to parse.

Nice work. I found it honest and down-to-earth. Sorry I haven't got any critique for you.

>To be honest,    
I still don't really know what happened.    
I know, sometimes,    

Maybe consider changing this part up a bit? Seems a bit contradictory but I'm no expert, just my opinion

First, I have to say that i really like your way of narrating the poem; it somehow creates the impression, the atmosphere of a lonely evening in my head, a person being rejected by the person he/she loves is not an uncommon topic but what i like about this approach is its sincerity.

As a user before me mentioned, you could consider changing V. 2-3 and use a synonym for "know" to avoid repitition.
Regarding the line breaks ... are they placed intentionally or intuitively? You could consider trying to use the line breaks as a formal structure supporting the structure of the content, as you (i can't tell if intentionally or not) already did in V.4-6, where you seperate the two sentences with line breaks and an "and" in a separate line, all by itself. I like that.

To be honest,    
I still don't really know what happened.    
I know, sometimes,    
"Things are better left unsaid"    
and    
"Everything happens for a reason."    
But no vague advice from a fortune cookie can change the fact that    
our lips definitely touched that night    
and,    
despite your insistence on being alone,    
your eyes always    
begged for me to stay.    
I took an on-line love quiz and    
scored a 90% chance that you love me.    
I was always told you can't really argue with numbers,    
but I guess the numbers lied    
and your eyes played cruel tricks    
because I'm still sitting here    
looking to fortune cookies for advice    
and taking on-line love quizzes    
to ease my broken heart.    

https://www.reddit.com/r/OCPoetry/comments/3uz7tn/all_these_dreams_now_theyre_dust/cxjk81w  https://www.reddit.com/r/OCPoetry/comments/3s5dnp/a_wife_speaks/cwuqesv

On-line love quizzes