This is copied from a comment I left at Maverick Philosopher. There is a characteristic of emotions that doesn't seem to apply to love, and a property of love that doesn't seem to apply to emotion.
One characteristic of emotion is that emotion is involuntary; it is something that happens to you rather than something that you do. Of course you can take actions to make an emotion happen (like eating ice cream to be happy or watching a sad movie to be sad) but this is no different from other involuntary actions. You can make your leg jump involuntarily by tapping your knee with a rubber hammer or make yourself vomit by sticking a finger down your throat. Just because you can effect something does not make it voluntary. If you want to feel an emotion, you have to do something indirect to make the emotion happen to you. They are essentially biological in nature. Of course you can suppress emotions, but you can also sometimes suppress other involuntary actions. Emotions are essentially biological in nature as shown by the way that they can be effected by drugs.
By contrast love is, or can be voluntary. It is not biological, not effected by drugs. You can chose to love someone. We sometimes feel that love is thrust upon us, but I think that to a large extent this is because we aren't paying attention to our decisions. If you meet a woman and find her very attractive, go through the dating process and become infatuated, you may think that you "fell in love" with her. But there was an alternative to falling in love. Instead, you could have chosen to view her as an object, enjoy her physically, and then be on to the next conquest. The fact that you fell in love shows that you chose to make her wants and desires your wants and desires. You didn't have to do that. You may have been prompted to do that because you felt that it would maximize your own pleasure, but it was to a great extent voluntary.
The characteristic of love that does not apply to emotion is that love imposes responsibility. If you love someone then you have a responsibility to consider that person's wants and needs --a greater responsibility than you have for others. When you tell someone that you love them you are, among other things, representing that they may rely upon you for support, both physical and emotional.
By contrast, emotions do not impose responsibilities or other ethical situations. If you are happy or sad or angry, this does not create a responsibility for you to do anything. If you enjoy someone's company then this may prompt you to care for them, but it does not create a responsibility to do so.
Since emotions are involuntary and biological but love is voluntary and non-biological, and since love creates responsibilities but emotions do not, love is not an emotion.