Guilt for Wanting another Child

I think that is one of the things that I was not ready for with secondary infertility - when we went through the years of pain the first time we were able to avoid kids and babies for the most part - it was certainly not a daily reminder - but now I am surrounded by kids and ladies who keep getting preggo with #2, #3, and even #4 - and often complaining about it - it puts me over the edge at times! Ladies I know will just plop a baby in my lap while they go to the bathroom or whatever - not even asking - and I have to hold back the tears. I used to hope and pray for one baby. We have such a gift and I know it and I am so thankful for her everyday! The guilt I have for wanting another is with me all the time. I feel like I am being so greedy - although this thought would never cross anyone's mind who had not gone through infertility . . . I also feel like I am not just failing me and DH but now I am failing OHA for not being able to give her a sibling - I guess the guilt will always be there.