Serious jealousy problems?

I've been really jealous right from the beginning. When I was a toddler I got jealous when my parents held other babies. when I was a kid, I would he jealous when my friends played with other people. Now I get jealous of other girls really easily with my bfs. I'm in a committed relationship now which may or may not last til were old enuf to be married. Yes I'm only 16 so I'm not saying anything. But I'm scared that I may never get over this problem. What if I get jealous of things in the future like my kids and their achievements ? Or other stupid things? I need to get over this. Any advice ?