Need Help/Advice

18M.

I feel really emotionally beaten down and I don't know what to do.

For reference or background - I come from a really financially and socially blessed background. My Dad is a doctor and makes a ton of mōney from his clinic and legal consulting he does on the side. I don't know my parent's total net worth exactly but I do know that we are well within the top 1% in the US. I'm going to start studying Finance and Pre-Law in that fall at a T10 institution for business (according to US News), which my parents are paying for completely in full and if I choose to go to law school they will pay for that too.

All that being said, I feel really really broken down and tired. I feel like I'm always doing something wrong and whenever I go to someone to just vent people always point out everything I've done wrong. I feel like in every bad interaction is always my fault. That on top of the fact that I do have so many good things and have a life "better" then basically the rest of the world makes it hard to say anything because there is so much in my life to be grateful for. I feel like whenever I say anything people just think I'm a naive rich kid. Again, I know I am very blessed in that way but its very hard because very few people are willing to just listen to how I feel.
One of my grandfathers worked as an engineer and the other worked as a politician. As mentioned earlier, my dad is a pretty successful doctor, and my uncle worked at an elite counsulting firm for a long time before starting his own (seemingly successful (?)) construction firm. It feels like I have to do something on that level (finacially and prestige wise), especially since my brother failed out of junior college and had to enlist in the Air Force, and so I'm the only one to carry on a pretty high preforming legacy.
It is kind of to the point where I don't know if my interests are things I'm legitimately interested in or if I just convinced myself that I find them interesting. I do feel like I'm genuinely interested in business and financial transactions and I will even watch lectures on tax law and m&a deals in my free time, but it feels like thats a really boring abnormal thing to spend your free time learning about, especially in high school and it feels almost preformative, even though nobody watches me do it and I don't really talk to other people about it too much.
I also feel like I have a huge pride problem too. As mentioned earlier, I am really blessed and I truly am proud of what my family has accomplished in terms of tangible success, but I know thats leaking into my relationships and feels like elitism. I have a sister who is studying art at a small liberal arts college and I have found myself thinking and saying nasty things about her wasting time on a "useless degree" and a "stupid" career path because she wont make as much mōney if she did something like banking or corporate law, and I know its really hard on her because my parents have told me as much, but I still feel resentment to her over it and ir makes me feel miserable. Part of me wonders if I'm maybe a little jealous because she has more freedom to pursue what she's interested in without the worry of having a super elite prestigious career.
Anyways, I find it really hard to relate to people because of everything mentioned above. I have a hard time even relating to my girlfriend (who comes from a semi similar background (her parents are rich but not nearly as much as mine)). She is Asian and I'm white, so their are some cultural issues or differences that could also contribute to that but. I feel very guilty for feeling this way because I know I should just be happy because I have so much going for me, but I just can't feel happy or excited about anything. I feel like I should be excited for uni but I find if hard to be excited for that and havent even looked into anything recreational or things to do in your "free time" other than career oriented clubs, and I've been committed for almost 3 months.
I feel so much pressure to preform and excel and live up to expectations and I don't know what to do. I feel like I'm just a nasty arrogant person and it feels like so many people idealize my life and having all the blessings I have and its just very hard to hear about how good my life is when I'm struggling so much.

That was all pretty incoherent and I did need to vent a bit, but if you did read through it all or some of it and have any advice about how to be less arrogant and deal with stress or anything at all about any of this I would really appreciate it.