Aw, I've been there, I know exactly how you're feeling
I know it doesn't feel like it now, but it WILL get better. You almost have to go through a 'grieving' process. I felt like my 'daughter' had died when I found out DS4 was a boy. Like you, I just KNEW he was a girl. I was shocked and horrified. Its a horrible feeling...the pain but then also the guilt of feeling like you don't want this baby boy. But really, time heals and you will love your new little baby more than you realise. The GD wont go away but I guess we all just have to learn to accept what we are given. As frustrating as it is!!!! All the best and big (((hugs))) to you..you are definitely NOT alone.