Both “I can’t love you anymore” and “I can’t love you any more” are correct, but they mean two different things.
“I can’t love you anymore” means “I can no longer love you.”
“I can’t love you any more” means “my love for you cannot get any stronger.”
When you have to pick between anymore and any more, you need to determine whether you want to indicate time (anymore) or a quantity (any more).
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