Regular moderators don't have any extra control over the VMs of others so unfortunately I can't do anything. Only higher staff can do that and only they have the power to hard-delete messages.
You can delete any VMs you've received by clicking on the little box in the top-right hand corner of each message, then scrolling down to the bottom of the page page, selecting 'Delete Messages' in the dropdown box and then clicking go. If you feel like you want to delete all of your messages for whatever reason it will take quite a long time.
Just out of curiosity: Are you trying to quit PC or something? Don't feel pressured to answer this though :P