Problem with my Parents

I'm not sure where else to post this, so here we go.

I am about to be a Junior in college. I am a Nursing Major, going for my masters ASAP to lead my way into becoming a nurse prac. I am only 20 years old.

I have problems with my father primarily. I am told I am irresponsible because I do not obtain perfect grades. For example, I made 2 B's and the rest were A's for the recent semester. He pointed out today I disappointed him for not making the President's list and only making the Dean's list.

It really hits on my self-esteem because in high school I was the perfect all-A honors student. My parents rarely paid attention to my grades and I still excelled. And now he asks "what happened?"

It's just the mentality of college is different. Things are harder than expected, and I slipped up a bit. It's like he forgot what it's like.

I don't exactly party or stay out late, though my parents insist I do because they track my snapchat map.

They recently got me a car for my birthday, and insist I am ungrateful. I don't know how I could show them I am grateful...I can't pay them back now, I'm a student in debt. I thanked them ten times over, but it isn't enough. This car is another way to track me, through a GPS app on my phone. They can shut the vehicle down if they wanted to, lock the doors, etc.

So, though I am 20 and supposed to be learning to be a responsible adult like they want, they always have me on a leash. I can't leave the house when I'd like (staying home for the summer) or go for a drive. I can't go on a walk or have a friend pick me up to go out. I am stuck until I can pack and leave again for fall semester. I have watch my 12 year old sibling because they "can't find anyone else to watch her." She's 12, not 2. If I were to leave a few hours to volunteer like I want to, I doubt she'd do anything miraculously damaging to our house. She has to learn some responsibility too, I won't always be there to watch her.

I'm just so frustrated because I am constantly torn down for being irresponsible and inadequate when I can't even prove to them how responsible I am. I just want to be able to drive off and do something on my own without feeling stuck or constantly monitored.

(Note: this is my first personal car. I would drive my dad's car when I rarely needed to in HS. They drive me to and from college)