Hi I am working in Qatar...and now I am going to...

If your visa is canceled, you will be banned only if you have committed a violation in accordance with the provisions of the Immigration Act
So you can go back and work in Qatar after getting the necessary approvals without banning on you

Article (24):
If the Foreign National does not obtain a Residency Permit in accordance with this law, then he must leave the country.
The Foreign National must also leave the country within 90 days if his Residency Permit expires or it is revoked for any reason, or if the stated purpose for which he received the Residency Permit has expired.
The Foreign National may, with authorization from the Competent Authorities, re-enter the country provided that he has fulfilled the conditions necessary for entry, as prescribed in this law and its implementing regulation.