Do you do auto updates ? If yes, machine could be trying to install updates and you killed it. Now, please leave it on wait and hope it can recover it self. After 2 hours, please check and post back.
I did that very thing this morning. Except I left it for 4-5 hours. But when I came back nothing had chnaged. Same problem.
I should also mention I'm not getting any response from the keyboard or mouse. Have also tried ctl-alt-delete without any success. If I could get to a restore cetting I could use that. Also tried holding F8 during bootup without success.