Given how the only love i've ever had were unanswered my picks will both be a bit depressing.
First off is Fran Oceans "Novacane". You know that feeling when you only can experience emotion when it is connected to a girl? This is about that, one of the few original "Love Is A Drug" songs.
Second is "Fire Bomb" by Rihanna. Yes i know Rihanna is not cool to like/is destroying music but fuck it, this song is awesome. It's about those times when you are so filled with love/hate that you feel like exploding/killing someone.