The best book I've seen on jealousy is "Polyamory" by Dr. Deborah Anapol.
I'm not pushing a polyamorus lovestyle, and neither is the author. After reading the book, I decided polyamory isn't for me.
One thing to note about jealousy. Although I have no insight into your situation, I have noticed that my jealousy has never been groundless. It may have contributed to my relationships ending faster, but in retrospect that's for the best. Jealousy is what I feel when you love someone, yet I do not trust them. In every case, there was a valid reason for distrust, and following my instincts at an earlier state (initiating a breakup myself, rather than clinging to hope that my jealousy is unfounded and trying to "cope" with it) would have saved me a great deal of pain.
