Help, finding peace within my self.. extremely depressed randomly atleast once a day?

What you have is an, I could do better complex. Why? Because you can. and you are not. I know exactly what you are going through. Its actually easy to fix. By your talking about your grades, you must not be satisfied with them. Now you think, would it have killed me to put a little more into my school work. You have let superficial things come first. Putting your life deciding duties second. Like your school work. This dreaded occurrence you foresee is your mind telling you, if you don't change a life unfulfilled will be the outcome. Its not just grades. Its life period. I'm sure that you put things on hold, that you know you should be doing. Like I'm going out with, whoever, so i'll do that later. When you do, do what you were supposed to, you did a mediocre job that you were not satisfied with. Remorse entails. Stop all the foolishness. This doom you anticipate is real. But, do your best and it will cease to exist. If you are happy with what you did, you don't have to look back in regret. Or forward in dread, because you know that you will do it again. Whats past is past. Your life starts each day. Start good, finish good, no regrets. Have a happy life.