People in my life keep leaving me one after another...

The first most important person in my life that left me was my own mother. Even though 6 years has past since, the impact is clearly until today. I've been left all alone in this world even losing my own family...Without a source of living support, I struggle to continue life despite of me lacking the knowledge of managing my own financial expenses. Despite of not losing my loved ones, I seek for my need of wanting to be loved and cared... Ever since I continued my studies, I've meet a couple of people that cared a  lot about me. Particularly a final year student in my own college. She's more like a big sister to me and I love her so much...but things immediately changed only after a year. She graduated. Once again I've been left all alone... The last moments I had together with her was her convocation day, which was full of sorrow. I couldn't face the fact that she'll be leaving me forever. I won't be getting to see her again. Though she's not even my own sister, but the feeling of losing a loved one is still the same, similarly strong, strong enough to break me down, falling to the ground... But time has past on. I've been continuing my lonely life all alone... by myself... I found a person that became close to me, and she cared for me. It's surprisingly weird knowing that some people would even want to know me, but she did. So I returned the favor by caring for her. Our relationship grew close together and since she's a year younger than me, she became a younger sister to me. To me, I couldn't care for my own sisters, so, I'm returning the favor by caring for her. She often shares her problem with me, no matter if it's her personal matter or not. And I would do all my best to help and ensure her happiness. But everything has it's limits... It turned out that I'm not that significant that I thought I could be to her... Her relationship with her couple cured up. I'm happy with it, in the same time feeling the sorrowfulness gaining back on me. It's not that I don't want her to be happy, but she's slowly leaving me back, and I'm slowly parting away from her attention. I think the time has come... my job here is finished. I've done what I'm supposed to do, and go back to what I'm supposed to be...alone. Things wont stop hitting me on the back, for me not noticing the lost of another significant person in my life, my uncle, the person that cared about me since the day my father left me. The feeling of sorrow is getting worst, the grief...it's equally the same as how guilty I feel not getting the chance to apologize to him. He scolded me ignoring my own father last year, the last moment that I ever saw him. But my ego keeps telling me that no one understands what I'm going through, and why I hate my own father. Now he's gone, never coming back, leaving me in this state, sinned. What have I done to deserve all this? What have I done to be left alone? Am I fated to be alone for the rest of my life...?