Ttc and having a very bad day :(

Chelsea
Sorry to vent on here but having a very difficult day. We are month 4 ttc #1 together (hubby Has a little boy from previous relationship) and I am losing hope. I had a mc a few years ago and I am paranoid that I will not be able to have a baby, it is my biggest fear and is taking over my life. Our friend has just announced she is 15 wks pregnant but all I can think is that having a baby is the last thing she wanted, not planned, shock pregnancy as she was on the pill and here I am desperate for a baby, trying everything I can and no luck. How is that fair? I want to be happy for her but I can't be as happy about it as I know I should and I feel awful about feeling like that. I may only be a few months into trying but hubby wanted to get married first so I have been waiting for 18months to start trying so it feels like so much longer than 4 months ttc to me if that makes sense. Hubby doesn't really understand why I get so upset about this all the time and I don't want it to effect us. Why is this so hard?