Jealousy is a very negative emotion. It can single handedly destroy a relationship. It can also destroy the trust factor and leave you feeling angry, bitter and frustrated. But it can be tackled by dealing with it effectively for that first isolate the cause of jealousy i.e. Identify the reason as to why you are jealous. As in every other problem just identifying it is half of the battle won. Then gradually and systematically eradicate or remove the factor that triggers your jealousy. Then slowly focus on building your self-esteem and the trust in your partner as well as your relationship. The first thing is building trust is to have faith in your love for each other in any relationship. It is not an easy task but with determination and will power it can be accomplished. You can also seek the help of a professional or your near and dear ones to smooth out your path in overcoming these problems.
Stop dwelling on past relationships, because they have a way of ruining present ones before you know it.