Wonky Granny Square! Send Help!

I need help from you gals who know how to crochet. 

 I have tried multiple times to teach myself to crochet. Without much luck.

But I really want to make a Giant Granny.

Reading crochet pattern illustrations is like Greek to me.

And I barely know the names of the stitches.

But after watching eight really bad crochet instruction you-tubes, and finally one good one, 

 I think I kinda-sorta-maybe got the hang of making a loop, changing yarns, 

turning corners and "three double-crochet in the gap".

Now I am on row #15 and my edges are wonky and this square won't lay flat.

What on earth am I doing wrong now?

Help!

(I need more work on choosing color combinations, too. But a girl has to start somewhere.)

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PS- for those who are trying to help me figure this out, this is what I am currently doing:

For the sides- three  double crochets and chain one

For the corners- three double crochets, chain two to turn the corner and
three more double crochets in the same corner.

 To go up to the next row- I pull through (slip stitch) in my new color of yarn and then chain two more
to make a chain three and that becomes the first section of the three double crochets on that row.

My sides are larger than the middle. And it seems twisted.
The corners don't usually seem tight to me, although I do notice in the photo it looks like it in the top left corner. 

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Update:
Someone suggested that I try turning the work from back to front between each row.
And that seems to have solved my problem.
Thank you so much!!