Am i crazy or is there something wrong?

Am I crazy for thinking this way?

I am 21 years old and I just completed my junior year of college, I've made the deans list every semester and I am on the pre-medical track. I am applying to medical school this summer as well as studying for the MCAT. In total it cost $800 to apply to medical school in addition to my MCAT exam. I have gathered the money and am ready to pay this entire thing on my own. I really had no intent for ever asking my parents for help whatsoever because they have not contributed thus far. I work extremely hard, I mean studying for the MCAT alone is full time 6 days per week. I damn near killed myself to get $800 in just a short time.

My family doesn't have tons of money so I've couponed (extreme couponer) to help my family get things they need, we have a basement full of toilet paper, paper towels, detergent, soap, deodorant, lotion, razors, etc. I've found the deals, paid for the coupons and purchased the items all with my own money. As a full time student that is the absolute best I could do to help my family out and I know they have saved thousands of dollars because of me. I'm not a bad person, I pretty much go to class, study, volunteering, community service, involved in clubs/organizations and tutor on the side for cash. My family always tells me I work so hard, and brag about me on social media but really dont do much for me. Sometimes I've used my last dollar to help my family out and was left with nothing for myself. I have been in the position at school where I almost went 2 weeks without food and had to iron on patches to my clothes, I've been sick and no money for medicine.

My brother on the other hand is the complete opposite, doesnt really care about school, he just graduated high school, more into hanging, smoking marijuana, etc. Does not really do anything for the family other than taking out the trash after someone jumps down his throat. My dad bought him pretty much a brand new $20,000 car, and pays his car insurance, so my brother spends his entire paycheck on expensive clothing and fast food. He always tries to make comments about what I wear and calls me broke, or laughs because my phone is older than his that I had to pay for. He plans on going to a community college part time which I am really proud of him I hope he sticks with it. My parents have been more focused on his graduation party than this being a hard part of my life applying to medical school and taking the mcat. When I called my dad and told him the situation Im in he said WOW thats rough. So I busted my butt and got the money myself.

I have to walk everywhere I need to go. At my age is embarrassing when someone says are you parked out front. I always have so many things to take care of each month any never really have any money left over for myself. I found a pretty decent car online for $800 which realistically I dont even know if I could save for. I mean all my time is in my MCAT exam right now, I wish I had freedom. I've lost so many opportunities clinically or shadowing opportunities because I dont have a car and I live in a rural area. I just feel like I work so hard and have nothing to show for it while my brother lives a life I dream of.