(please keep all negative comments to your self. I'm asking for help and advice)

I feel like the worst mom ever. But I can't shake this feeling of overwhelming sadness and disappointment. I have a beautiful 7 year old daughter. I really really wanted this baby to be a boy. We found out yesterday that we are having another beautiful girl. I just can't seem to get out of this sad funk. I know when she is born it will not matter, she is going to be my second lil princess. Has any one dealt with feelings like this? Thank you for your advice.