Rumplestiltskin has long taken it for granted that Belle is willing to fight for their relationship and is constantly doing so. But now he's lost her in the worst way – physically she's there, mentally she isn't – and he vows never to take her for granted again… if he can get her back.
He's used to fighting for Baelfire – he's done that for nearly as long as he can remember – but fighting for Belle is a different and new game entirely. In a way it's harder, because he doesn't know what to do. But he knows he'll do whatever it takes.