It's much harder the way society has changed so that people have so many intimate relationships in their life rather than mostly the one that everyone use to aim for in their lives......this insecurity & feeling of jealousy is the price we pay for the way our relationships have evolved over the years. We either accept that the people we are with have had many relationships......or we look to find those who have not believed in living that way (& there are still people who do not choose a many relationship life)

Add to that, being insecure about self doesn't help those feelings either......when you don't feel equal to those previous relationships, then obviously, there's some level of insecurity that one is dealing with.

Hope you are able to sort thru your emotions.