I am Under Attack.... WTF

[hotrod]

I just started getting pending orders... 1 every couple seconds.  they some how added a product to the cart the had no price and no add to cart..  I looked at the logs and banned the IP but didn't help..   I had to put the site into emergency Off Line Mode with admin tools...   That stopped it..  I waited about 5 minutes and when I put the site back on..  they started coming back in..   WTF???   

I found the Ip and blocked it in cpanel.. that seemed to stop it..  but I can't understand how the got a product in the cart that didn't have an add to cart..  it had no price.. 

146.19.230.52 reported as spam and brute force attacks