There's always going to be an element of favouritism in families, my younger sister is certainly favoured but there are clear reasons for this. My mother had me at 18, clearly not planned, then for years they tried for another and had several miscarriages, eventually at 27 my mother had my sister and she's had a few minor issues along the way which have been corrected surgically. She's a perfectly normal child but my mother is obviously more protective, since I have never so much as broken a bone. I came along at an inconvenient time and my sister was a child they were desperate for.
I have no real issues with this, my main issues with them are those of control. There's a definite power imbalance and my father has been running some kind of dictatorship since I was about 9/10. He came into a large sum of money after a relative died and turned into an even worse version of his irritatingly controlling former self.
So, no. You are not alone, my father is hardly abnormal nor are the dynamics of my family. Granted I don't live with them anymore and I would recommend you do the same.
The funny thing about family is that you are expected to love them no matter what, simply because you are blood related. The sooner you realise that it's normal to dislike them or not love them at all the better. Would you love them if they weren't related to you or if you met them on the street? It's not likely.