What do you do when everything's just going wrong in your life?

I just got a letter today saying i'm on academic probation at sch. I failed one course last semester and didn't do so well on another. They're giving me a chance to get better marks next term or i won't be able to get student loans for a yr. I've changed programs a few times at sch and right now i should be graduating, but i've nothing to show. I've been trying to figure out what to do with my life, which path to take and that's one of the reasons i didn't do so well. I was so lost n confused with myself i had lil' motivation to study. And i'm always very studious. I have no summer job right now, absolutely broke, 21 yrs old (22 on July 1), no friends, no confidence. I feel so alone and like there's nothing for me in this world. I don't think anyone in my family really cares for me and i know my parents probably think i'm a disappointment, and lately i can't help but think that too. I'm a christian, but lately i don't even know what to think anymore. I've been thinking about ending it all, i don't even know why i'm here. I don't even know who i am anymore. I'm so lost; i'm not living, just barely existing.