Suicide is generally short-sighted and selfish. Unless you're suffering from some terrible disease that you'll never recover from, there's every chance things will get better. You may even be able to use your experience to help others in a similar situation later on (which is what many suicidal people do, after they've come to their senses and come out on the other side of whatever's brought them to such a place). Imagine that: you not giving up might inspire others not to give up, and now you're officially a lifesaver.
If that isn't enough, consider what it will do to the people you love. You'll basically kill your parents, whose lives will never be the same and will never be truly happy again. Your brothers, sisters, friends and significant others will all be haunted by it, blaming themselves for not helping even though you never reached out or they didn't know how to handle it. You taking the easy way puts all that on their heads, and they'll never be free of it. That is just about the worst thing you can do to a person.