Did James Bond ever really love any woman?
In Casino Royale he was deeply and sincerely in love with Vesper Lynd – both in the most recent film (2006) and in the original novel (1953).
Casino Royale was Bond's debut – and right from the start he is confronted with the issue that a woman he loves betrays him; actually Vesper turns out to be a double agent that was blackmailed to do so and commits suicide in the end, but Bond compensates this loss by suggesting to himself that Vesper had been evil all along: him saying "The bitch is dead" can be both read in the novel and heard in the movie.
The real trouble: this experience shapes Bond to become the person we know – a cynical, cold hearted, mistrustful killer who struggles to avoid romances at any cost.
So after all, his sixty-minutes-marriage to Tracy in On her Majesty's Secret Service is a "weakness" that he allows himself – and he is brutally punished for it again.
You could say that his marriage to Tracy was merely a desperate attempt to get out of Secret Service and starting to "get a real life" instead – it is not only about love but also about clutching at a straw.
Aspointed out already, his real connection to Kissy Suzuki in You Only Live Twice is probably not even known to the cinema audience: in the novel, Bond suffers from amnesia and believes himself to be a fisherman (this happens after losing Tracy, because other than in the movies, YOLT was written after OHMSS). Then he falls in love with Kissy – and even has a child with her! But he has to leave her before he can find out about that. But the most important thing with Kissy is indeed Bond's amnesia – it allows him to fall in love at all because he cannot recall the person he used to be any longer.
This is the tragedy behind the James Bond character: he is doomed to stay personally unhappy in order to make his job as professionally as he does.