Is suicide really a selfish act?

I mean i understand in the act of suicide other people are hurt. Your friends, family, and other people close to you feel hurt. But people don't get it i have to live feeling this way each and everyday. I just get sick of the world shitting on me. People always just tell me to look for help, but when i told my mom once i thought about doing it she told me she'd give me the knife to do it. It gets harder and harder to keep going. I feel like a hit a wall and there is no way out. It's been like this since junior school. At recess in elementary school i was always the one that hung out alone. Then my parents verbally and sometime have physically abused me. My rare relationships always end fast and at the end of them i feel as if it is my fault. I not very good at anything no matter how much time i put into it. My grades also aren't the best even after staying in my room studying for hours. My self esteem is basically non-existent. So in the end am i really the selfish one for not being able to go on. I love all the people in my life and would never want to hurt them, but each day i'm alive i feel like i'm being hurt more and more. I watch all my friends and family with their success and I'm happy for them, but it also hurts to see when i'm always losing. So how could any of you who call me selfish for feeling this way have any idea what this is like without living a day in my shoes?