I'm sorry you are feeling this way. While I love having two boys, I'm gonna be sad if I find out I'll never have a daughter. I am pg with #3 and we are done after this one so I will feel the same way as you if this is another boy. But yes, having two sons is wonderful.
I wasn't sure how DS1 would react to having a brother either but he loves it! He wants to dress like him and even wants him to come everywhere he goes. Also, feeling differently about your second pregnancy may not even have to do with gender. I felt that way all along with my second pregnancy before I even knew the gender. I think it's exciting when it's your first time, but sometimes when it's your second you feel a little guilty cause you don't know how the first one will react and since you've been through it before, you might not be as excited. I feel I couldn't bond at all with the baby during my second pregnancy, even from the get-go. However, once he was born we bonded instantly and I immediately fell in love with him.