Welcome Jenna! You are in the right place. There are a lot of us here who have been through gender disappointment. I have to say, I can see why this is hitting you extra hard, given what you have been through with your DH. It must have felt like getting back together, having another baby, it was meant to be your daughter. But then it is like everyone else gets a girl instead. It does seem so unfair.
First of all, don't be hard on yourself. (You can always find someone else to do that, ha.) You didn't ask to feel this way, and being disappointed in not having a daughter does not mean you love any of your sons any less. It just means that you are grieving over a dream that is not coming true the way you thought it would with this pregnancy. It's not disappointment over a baby, it's disappointment over a dream.
If you can, take some time out to do something just for yourself, that will take your mind off of things and be a treat for you. Maybe just a pedicure, a bubble bath, or an afternoon with a good book. You deserve a little pampering!
Hugs to you,
Maureen