Not That Important

I just need someone to talk too I understand there are people that are going through a tougher time than me. I just need someone's advice or knowledge on my situation. I am currently enrolled in high school and have plans to making it to university. I am not the brightest student however i pride myself on my work ethic and perseverance. My mark are for semster one: accounting 88 %, international 88%, and economics 87%, the problem come at my adv function mark 71%. I did not slack off at all i tired everything I could to make my adv function mark at least 75 % so i can at least what a university requires. I went after school for help, i did all my homework, and ask question regularly in class. I wanted to redo this subject however it was full, night school as well. I talk to everyone in power and all i got was they had to be fair. I honestly do not get how is it fair that i worked so hard day in and day out and i just needed 4 % more and life just ***** on me. The worse fact is im not that rich either my parent just make enough to meet daily needs. I need to go to university and help out my parent and give them a better life they work so hard and i feel worthless that i can go to university i love knowledge and want to further myself so i can help my parent. Im so lost and confused i honestly dont know what i can do atm.... please someone give me advice