This is a very soulfull break up song. The point is, she loves him, but she doesn't want to, she's hurting. "I never wanted anything so much. To drown in your love, and not feel your RAIN." The love is the obvious love she feels for him, the rain is the pain that she had in the relationship.
So she loves him, but elements of their relationship hurt her. It seems like they've been broken up for a while and she is trying to get away but can't because she loves him. Then he keeps affirming that she can't rely on him, he's ambivalent to her. "You're neither friend nor foe though I can't seem to let you go."
The end of the song is somewhat hopeful, "you're onto me, onto me, and all OVER." She may be able to get over him. Of course, she has to go back on that a little bit by expecting to be drawn to him again. "Something always brings me back to you. It never takes too long." This is a beautiful picture of the confusion of a break up.