Immense server lag after reroll

After a reroll from 2 griefers that have been griefing for quite a while now, the server just won't stop lagging, after starting the server the CPU and Memory go to 100%, then CPU goes down a bit, and whenever someone chats or builds anything the CPU goes up again and the server gets a lagspike.

Is there any way to fix this?

Thanks.

- Atilla Bosma

Edit: This server is being hosted by Daddycheese.com, and it's 2GB RAM, 24 Slots.