Hi Elle,

Look up in your navigation bar, at the top of your screen.
You'll see an envelope type of image and it will have a number next to it, like (1)
Click on that number to access your inbox.

I sent the message from your profile and judging by your comments, I have a feeling that you might be confusing your profile comments with your inbox.

Profile comments are public, inbox is private, just to be seen by you.