Hi Sakin!
My site is http://www.voicesoftheselves.com
I discovered how to change key settings in Yoast SEO and then found this:
http://wordpress.stackexchange.com/questions/3605/how-can-i-control-the-facebook-like-image
with the instructions to add this to the head
<meta property=”og:image” content=”http://YOUR_IMAGE_URL” />
This allowed me to use an image from the media library that’s not on the front page as the image that shows up on Facebook.
I hope I got it right now…