TTC 2.5 years :(

So been TTC for 2 and a half years now, still with no luck and awaiting further investigation at the hospital. Today I found out one of my best friends is pregnant and as over the moon as I am for her it's jtust completely broken me, just starting to wonder if it's ever going to be my turn. Is anyone else in a similar situation or is this just me having a bit of a selfish day?!