Significant increase in database

I have just moved to a new host. After moving, my database increase significantly from around 500mb to more than 1Gb and my site always meet Fatah error especially when adding new post.
I already try to restored to old database but after 1 day it’s increase nearly 100mb. 100mb just for nearly 1 day.
Is my site be hacked?
I’m using Downtownhost.