From Whois and your account history, it seems like
1. You have had the domain for awhile
2. You have had the nameservers set to x10hosting for awhile
3. It has been your main domain on your account for awhile.
Is this right?
Edit/Add:
Looking at your former posts, it seems that all the answers would be 'Yes'
For some reason, ns1.x10hosting.com does not contain your domain. An Admin will have to fix the nameservers.
Escalating to a Support Ticket. This will close the Tread, but you can follow the Support Ticket by clicking on the yellow bar at top.