What are possible pychological reasons behind my mother discrimination against me?

How does she discriminate against you? Please give a couple of examples.

I have three brothers. She registered my brothers at a private university; she taught them driving; she bought them cars; she built them houses; she take care of them too much and cook what they like; she asked her brother to hire two of them at his company

For me; I was at an official university (free); I started working before them and I got a job that I need a car to go to it but she didn't taught me how to drive; I bought my own car from my own money; I financially contribute to the family; I do house work and they don't because I am a female and they are males. She doesn't care if I have a house or no! She built the house to our older brother; then skipped me and moved to my younger brother; and asked me to pay big amounts. I covered her travels and changed the furniture at the family house and she told my neighbor s that my brother did. She is careless about my things while she is not when it comes to my brothers' things. I always buy her expensive gifts and take care of her; take her out but she doesn't even count me when she cook. She use my things carelessly and ruin it then says it wasn't good. She is rude with me In front of the family while she is not with my brothers.
I moved to another city and living in a shared rented apartment with my friends; but still I come find everything messy and dirty; and she always disturb me and frankly speaking I hope I can skip ruining my weekends by coming home and serve everybody. But I am emotional and this will also make me sad.
Hope you understand me. I registered to this platform for the first time in my life to ask this question because I want to be happy. I am 31 years old; I have a good job; all people say that am very successful but am not happy. I don't think my success makes my mom happy, I guess she wishes it for my brothers..

May I ask -- what nationality are you? The social norms of your country are very likely what is causing this -- e.g., male children are more valued than female.

I can only suggest you spend more time making yourself happy and a lot less trying to please your mom. It does sound very much that you are in a society that greater value is put on men than women, and your mom was raised that way. She probably went through the same thing that she is putting you through.

Where is your dad and how does he treat you? You make no mention of him, or your relationship with your brothers.