No, although the meaning is quite close. "To be in love with" is "být zamilovaný do + Gen".
This is an unnatural English sentence. What does it mean? He loved her then, but he doesn't love her now?
I think the English sentence is OK. It's the situation the sentence is describing that is unusual.
I think it depends on the context, and it need not be negative. Imagine this conversation: Q: You two seem to be getting close. Do you love her now? A: I loved her a week ago. And now I love her even more.