What counts most in life is the journey. There are ups and downs in everyone's life, and even if the downs are farther down than most people's, keep on going and wait for an up. Things won't get better if you don't try to look at the positive and try to make things better (I know there isn't much you can do about your family situation, but you can still look at the positives and focus on something else to take your mind off that for a bit). I really don't know you well enough to give good specific advice, but don't give up so early in life.

I'll add you to my prayers for your mother and grandfather.