Why should I keep living?

I don't see the point. I feel as an ultimate failure. I don't plan on killing myself but I still feel like "it's the only way out." I just had a huge car bill over $2000 for fixing my car. There were so many things wrong with it that the mechanic suggested poor driving. Everything he listed as the poor driving, I do not do and my parents don't believe me that I don't. I feel like a piece of crap not having their trust. I don't have the money to fix my car, and my parents keep emotionally black mailing me to get something done to the point where I can pay them back for the carBut working part time and being a student full time there's only so much I can do in terms of being able to pay for my car. I could use some words of encouragement. I know I have a bright future ahead of me . I am 18 years old studying criminal justice in college and getting my name known in police departments for a future career in law enforcement, but I just don't feel like I "can" make it there. I have lack of really good friends, never really had a girlfriend. Just wishing stuff would change and I do do my best at trying to make things work but this time I am falling short on seeing why I should continue or why I should move on. Thanks for reading this whole thing, hope someone has a decent comment to make me feel a little better and good heart that will help.