Macintosh HD won't erase

I had trouble with starting up my MacBook so had to proceed to wiping everything and starting afresh.

I selected the recovery and everything, utilities, Macintosh HD etc clicked erase, and where it says erasing volume, the blue bar has moved so far

And stopped. Hasn't moved any further in about 45minutes.

Is there something I can do to wipe everything off my Mac and start afresh?