Read/opinions on my essay?

Hey if someone could read and tell me what you think of my college application personal essay that would be great. It’s not quite done so it’s not polished yet. Thanks!
and if you don’t think it’s good, please tell me!!

I knew what was coming. I felt my heartbeat quicken as I prepared myself for the challenge that lay ahead. This was my opportunity; I was going to finally do it. I inhaled sharply, dizzy not from thephysical exertion of peddling, but from the anxiety spinning inside my yellow helmet. I was almost at the top;I tried to stay calm as I slowed the fight against gravity. I watched as my parents shifted their gears higher, the clicking indicated that the time had come. I didn’t want to go faster-I liked the uphill pace: slow, steady, controlled. As we reached the top of the hill, I put my breaks on, the small gentle slope ahead grew into a steep cliff in my mind. I looked down, I wasn’t ready; the sun was too hot, I was too tired, my shoelaces weren’t double knotted. Repeating every excuse I could think of to avoid going down the hill. I hesitated, and then, yet again surrendering to my cowardly excuses I dismounted the two-wheeler and walked down the hill.
It was never taking on a challenege that frightened me-as a cross country runner, I have always has the strength and endurance to get up any hill; what I was scared of was the loss of control that happens when a challenege took me on. When I was seven I could dismount and walk, but sometimes you don’t get that choice. When life throws you down a hill, taking on the challenge is not optional, it is inevitable. In the last few weeks, what I’ve learned is that not only can I climb up any hill, but now, I can get down them too.
Sometimes life throws you down a hill, and you don’t have the choice of dismounting. That’s what happened last week, when my dad, who had always been my training wheels, who had kept me centered and safe, died. I am spiraling downhill with confusion, wondering why this happened, and feaful of what is to come. I grip the handlebars in sadness and feel the shock that rings from the bell. Right now, the ride feels unbearable, and part of me wants to take a break, but I know I must stay on. Right now, I am speeding down the hill, and although it’s just as terrifying as when I was seven, I’m still on my bike. What I have learned in between my seventh and seventeenth birthday is how to keep myself steady, center my emotions, and prove to myself that I can keep going forward, I might need to change my path, and take a slightly different route, but I am proving to myself that I will keep on pedaling. I can keep myself safe, my training wheels have been taken off. What I have realized is that can I do it, I have the ablility to deal with this challenge.
I remember the first time I rode my bike to the bottom of the hill, wearing my yellow helmet. After the initial shock of completing the mission that I had tried to tackle for so long, I noticed that I was okay. I had done it, and I was still there, still on the bike. That is how I feel now, though I was thrown down a hill larger than any I have ever dealt with, I’m still here. And though in these past days it hasn’t always felt true, I’m going to get through this. I’m at the bottom, but in time I will be okay, I will push myself up the next hill, and if I have to, I will fly down the other side. And I will keep on going.