You can do a tag search here in these forums, for 'jealousy' and find many threads on it. There's a thread somewhere called 'golden nuggets' full of many wonderful tips.
Have you done any therapy? Could be helpful, especially since it sounds like you're recognizing the common denominator is you.
Love is that condition in which the happiness of another person is essential to your own...
Robert A. Heinlein
Me: female, bi, (formerly hinge of a vee)
with FirstBoyFriend (FBF)(moderately long-distance)
and no longer with CurrentBoyFriend (CBF)(who lives in the apartment building next door)