Hero to zero

So I'm a high schooler and when I was younger I would get full marks nearly in everything and I cared alot about my grades I barely did anything other than studying but in middle school my grades started to get lower and lower like from full marks to average then in high school I just started to get worst I barely pass even in things that was easy for me and all I do is watching people getting better especially that it's an important year cause It affects you college and things and I feel like I want to do anything other than studying and when I try to study I just feel like why I'm even doing all of this I have no purpose and I feel like I'm. It that good I need to do more efforts to just be as good as any other person sometimes and when teachers ask me anything and I don't know I feel ashamed of myself I always think about my old self even if the only thing she did is studying she was better it's not like I have a hobby now or something to do I just search for random stuff like days ago for no reason I started searching for a books about surviving for no reason and all I do is just sitting saying ohh why I'm not good ant this why I'm not like the others without even trying just telling myself this instead of gathering my sh*t and I just don't like when people tell me noo you're good you need to work harder and stuff maybe because it's true but that's not what I want to hear wonder if anyone will read all this😅 if you have anything to tell me just tell me if you want to vent vent I'm openly to listen to people