How can I alleviate my stress, lack of concentration, and symptoms related to depression?

Hello doctor,

I am currently in my first year of high school, and I find myself in a highly competitive academic environment where many students aspire to attend prestigious universities. The atmosphere can be quite stressful. My sleep schedule is often irregular, with me typically going to bed between 12:30 to 2:00 am and waking up at 6:25 am on school days, resulting in constant fatigue. Despite the challenges, I have taken the initiative to self-study three advanced placement courses and have set a goal to skip precalculus and progress directly to calculus by the tenth grade, as it is an available option. Although my classmates are incredibly competitive, I only feel comfortable around a small number of them. Nevertheless, it seems that, from an outside perspective, I am doing relatively well. I have achieved success in a writing contest, maintain the highest GPA in my grade, and qualified a math contest. People generally view me as intelligent.

Lately, I have been feeling increasingly worried because I have been having difficulty concentrating, and I cannot pinpoint the reason behind it. I suspect that it might be due to a lack of sleep, but I am also considering the possibility of having a mental health disorder that is affecting my ability to focus. I also participate in tennis, and up until this school year, I was quite skilled at it. However, for the past few years, I have been grappling with periods of intense misery that I hesitate to label as depression since I am uncertain about the exact nature of my emotions. I am not constantly sad, but occasionally, I have fleeting thoughts of wanting to die. Oddly enough, if a random car were to accidentally hit me and end my life, I must admit that I would feel a sense of relief. Most of the time, though, I feel predominantly tired and lack motivation for any activities. During tennis matches, when the ball comes rushing towards me, I find myself freezing and becoming confused, even though I know exactly how to hit the ball. Initially, I considered the possibility of being afraid of the ball, but given my willingness for a car accident to occur, I do not believe that is the case. I wonder if there is a mental disorder that could be slowing down my instincts and reactions, although I am uncertain which specific disorder it might be. While I experience both highs and lows, I generally have consistently low energy levels, which leads me to believe that bipolar disorder may not be the cause. I am deeply conflicted about this matter. My parents are rather strict and dismissive of what they consider to be ‘politically correct nonsense’, including mental disorders. They tend to view such issues as teenage foolishness and attention-seeking behavior. In contrast, I believe in the legitimacy of mental health disorders to some extent, especially since I have learned about their molecular causes in an advanced placement (AP) class. Overall, I am unsure about the factors contributing to my diminished ability to concentrate and lack of motivation. I have never sought medical attention for these concerns, and as a result, I have not been diagnosed with any condition or received any relevant medication. Please provide me with suggestions.