Does it get easier???

I have two beautiful babies and an amazing husband that I love more than anything!  I wouldn't trade Madi or Easton for anything out there, not even for a biological child.  I can't imagine my life without them.  I am thrilled being their mom and love almost every moment I have with them. (I say almost because I could really go without the temper tantrums :D).  I thought that once I had my own babies, the sting that comes when one of my sil's announces that she's prego would be gone.  It was with the last three announcements, but one of my sil's just told us all she's pregnant and it's back.  I think that with the other three, mine were still babies so it wasn't hard.  Now that they are growing up and I can't have a baby just because I want to, the sting is back.  :(  It isn't their fault and I am truly excited for them and thrilled to have another niece/nephew, I just thought I was done with this kind of hurt, and am struggling to find peace with it all.  I hope that someday I can learn to let go of the ache I have for a big family and be 100% thrilled for anyone that is having a baby and 90% thrilled-10% jealous.  So, for anyone that has been in my shoes, does it get easier or is this something I just need to get used to???