"
It's not more than one, if that's what you thought.
You'd say I don't have the time for you,
But I do
She wants to call but she feels bothersome. She doesn't want to call more than once because she feels like she'll be pushy, like an ex girlfriend trying to get closer to their ex. Her ex is telling her she won't have time for him, trying to convince her to keep to herself, possibly showing he doesn't want to be in contact with her, but she's insisting that time is all she has now that he's gone.