Am I just bring a brat or??

So a little background story - my sister is about 35, I’m 30. My sister has had a whirlwind of issues come up throughout her life and my parents have always bailed her out. They also paid 6 figures to her for her college and she threw it all away because she got a felony…I’ve been on my own, paid for everything on my own since I was 18 - didn’t go to college because I couldn’t afford it and my parents spent all their $$ bailing my sister out and couldn’t help me out. I’m now 30, married, have a house and daughter and made a good life for myself. We do want to upgrade, but don’t really have a good down payment to put on the house I want (and the market is crazy right now). I asked my mom if there is anyway I could take out a loan with her for a bigger down payment and she said no because she already gave my sister a lot of $$ for her new house and she has a loan out with her…am I a brat for feeling bitter and hurt by this? Like I’ve never asked for ANYTHING from my parents. I’ve supported myself since I was 18, have never gotten into any trouble, and they still are supporting my older sister…like wtf. It kind of makes me just want to cut everyone off but like I said I don’t know if I’m being a brat or have the right to feel hurt.