Loosing Hope

I lost my grandpa on Christmas eve. I thought maybe he would help me concieve, but no luck. I've been trying for a year, no luck, never been pregnant. Fertility doctors says totally healthy. I'm 37 and the only thing I ever wanted was a family, but I don't have one. I'm so down and depressed. I'm so sick of seeing everyone's engagements and pregnancies. I can't take it anymore. I was always the positive one but when is it my turn? Or am I just the one that won't be able to have children and family. I waited so long to do it the "right" way. I'm exhausted :(