Marriage and infertility

How does marriages last during such a struggle? Iam sure that's one of the reasons me and hubs aren't close! By this age we though we would of had 4 children by now! It hurts all our friends and siblings are parents and we are just the awesome aunt and uncle that spoils them! Idk what we will do if crap don't change! I dont want to lose him but I think all ready have!