PBR -- whatever it takes. I've sooo been there before and I am one who cannot deal w/ conflict or people being mad at me or me being mad at them. I have an evil explosive temper & I carry grudges to the point of self-destruction, so I know of what I speak
I"ve gotten a lot better w/ not taking things so personally, but also protecting myself a little more & keeping my expectations of other people very low so as to not get fucked over so hard. But you also have to let yourself live life - it isn't always a bowl full of cherries - sometimes you get one w/ a really hard pit. But it also takes the lows to really appreciate the highs. (OK enough philosophy...)
But I've found that I have to give myself a certain amount of time to "grieve" and just to bring closure as best I can. Then you hit the day when every extra second you spend feeling mad / sad / upset / pissed / jealous as a result of the other person, that it counts against you. Don't burn your precious seconds of life on something that is only destructive. You can't expect people to consider your emotions and often people are so irresponsible of their own emotions that they can come across as really mean, rude and disrespectful or manipulative of your emotions that you just want them to die in the flaming bowels of hell... and they may not even be doing it to be mean. They are just stupid. And it isn't your problem. They have to live w/ their own faults and its no longer your problem. Remember the good times & also revel in the person you have become as a result of your experiences with this person -- both good & bad -- because it has contributed to who you are right now. But also learn from it, rise above and be a better person for it. Especially if it is becoming apparent that the other person has not. So .. fuck 'em. Not your problem anymore, and they represent nothing more than a way to waste your precious time and efforts on this planet. So don't let it -- like Shadow said - Jealousy is a wasted emotion. Give it the appropriate amount of time to heal yourself, but then move on. The day you realize how inconsequential that person is in your life is the day you are truly free to enjoy someone who you can allow to be supremely consequential in your life.