I think that both DerpTastic and bioarch_fan have given you great advice. I would also add that it is so important to talk to someone about your suicidal thoughts. Do you have someone you can confide in? Perhaps a family member, friend, professor, or academic counsellor?
In my experience, one thing I realize is that with school, there is *always* a way to get where you want to go. My gpa was horrendous and it stopped me from moving ahead in my career. But when I was ready (in my case, years later), I went back to school and completed a make-up year, did well and got admitted to my dream school.
When the timing is right and you have all of your ducks in a row, you will achieve your goals. Trust in your abilities. The truth is, many people do not get into grad school the first, second or even third (or more) times. Sometimes all it means is that you are not as ready as you think you are and you need to fix something in your application or apply to more realistic schools. But having said that, whether you get in or not should never define you as a person. You are no better or worse of a person just by getting into or rejected from a school. Grad school is just one hurdle in life...you will leap it, just keep at it.
Just remember that success is rarely, if ever, a straight line from A to B. Disappointment is part of life. Instead of burying yourself under it, try your best to make use of it to help shape your next step. Be proactive and know that you are not alone. Again above all, please speak to someone about how you are feeling.