Depressed when thinking about past family life?

recently, whenever i start looking back and thinking about my family, i get really upset and depressed. my relationship with my parents now is fairly strained. i'm 19 and in college, and my relationship with them has gone steadily downhill especially starting over this summer. any time i think about the way things used to be, like learning to throw a baseball with my dad, or even simple things like how he used to make breakfast for me on sunday mornings sometimes during highschool (he doesn't any more, we barely even speak). i hate to say it, but even just typing out this question brought me to the point of tears. i definitely have my disagreements with my parents, but i miss the way things used to be. we were never exactly a happy family, but at least it used to feel like a family. now i feel like just an outsider to my own family, and it sucks.