OP, your story made me so sad. I am an only child, although my mum went on to have a miscarriage, followed by a mole pregnancy followed by 2 stillbirths. She would have loved a boy, as in her family the boys were favoured and she was happy to run around after her brothers. She was frustrated that I was not a girly girl either, but we had a good relationship nonetheless, albeit a bit volatile at times. I was closer to my dad, we had more in common and I think she felt a bit left out. She died when I was pregnant with dd1.
My dad was bereft, and he still misses her 14 years later. He will never remarry, I Dont think, and we are still very close (he lives next door to us and looks after the kids when DH is away, comes on holiday with us every year,and is a huge part of our family) By no means are most men like your dad.
My dad always said girls were the best (Im sure because of his relationship with me!), and he was delighted when we had 2 dds. When ds came along I was actually a bit worried about how he would be, but he loves ds every bit as much, and he actually has more in common with him than the dds, especially as they all get older.
I can understand someone secretly wanting one sec more than the other (I was delighted to have ds, but another girl wouldn't have been a disappointment). But I genuinely believe in relationships with your children you get out what you put in, regardless of their gender.
At the moment my dd s are 13 and 12, ds is 9. The girls are great, but they have issues with their friends etc, and I spend a lot of time listening, trying to help, getting shouted at, getting cried on, wiping tears, cheering up, listening some more. Ds has just come down and been reduced to happy hysteria because I made a funny face at him! Swings and roundabouts, and the relationship constantly changes at each stage of their lives, but that's what I love about being a parent!