Its been awhile since I've watched DS9. Odo was fine without going back to the Great Link and didn't dissolve into putty. He just needed to go back to his bucket every now and then.
So why did the emo-changeling go into withdrawl from not being with the Great Link? If he really was a changeling he could have ducked into an alley and turned into a bird and fly away like Odo often did.