Domain Name Server Issue Im A Bit Confuse

HI I Already Installed Wordpress Multisite on My Domain , i installed other plugin, successfully,
Just Now While Im Testing Other Plugin my Site Just Dont Point Back to My Domain Name again?
I Dont Know How i can Resolve this Thing
I Already Have it Pointed Correctly in the Correct Name Server, My Main Question is why is this happening, automatically, and How can i Fixed this coz i cant do anything in my site unless this keep pointing in somewhere else , and is being parked to other....

Please help thanks