Depression.... Please help!

I have been TTC since October and I have had no luck! It seems like all the people around me are having babies and expanding their family besides me and my husband. Our friends, family, and co-workers are pregnant. I am having a hard time in understanding why it isn't me. When someone else tells me they are having a baby I am happy for them but on the inside I am screaming" why not Me" I am coming to the point where I just want to stay at home and cry! Any advice on how to deal with this would be great! Thank you!