Good take. It's been a while since I read the book. (Probably haven't re-read it in your lifetime!) But I think Gatsby loved her in a semi-selfish way back when they were younger, because of the way she made him feel. Now he's rich and he thinks that if he can get Daisy, he can recapture that feeling.

Tom of course doesn't really love Daisy. She's just one of the things he has, part of the visible display of his wealth.