This made me feel like Im failing my parents

I'll be 18 next year, that means I'll be going to college. The cost of living is high, even if I tell them not to send me to college for now, I can't do it. They sacrificed so much just so I could study, seeing that they were struggling to give me a bright future breaks me in a way that I started thinking negative thoughts. I thought, should I just commit suicide to reduce expenses? Or maybe if possible, I can exchange my organs for money to help before I die? I know how selfish they are because they did everything and then I'll just end up thinking of ending myself. I don't know what to do anymore. I want to reduce expenses, headaches, and extra worries at home. Even if it's just my sister who goes to school, that would be fine. I'll just help out and work. I feel bad thinking about this thought but I can't stop thinking about it. I feel like I failed them somehow before I could even do anything