Assume, just for a second, you have a car. If it breaks down, what do you do? Normally, take it to someone to get it fixed. You wouldn't pour acid on it, blow it up, drive it over a cliff. It's just broken, and broken things can be repaired. You are no different to a car (assuming your issues are emotional, and not physical). You have a problem, and part of that problem is that people don't see ill health of the mind as an illness which is just as serious as any physical illness. But illnesses can be treated. The issue is you either don't believe you can be made better, or don't know how. Both can be addressed.
On www.metanoia.org, Martha Ainsworth uses a slightly different analogy, and talks about suicide being driven by a person getting to a place where their pain exceeds their ability cope with the pain. I think this is also true, and the trick is to either reduce the pain, increase the coping resources, or ideally both.
So, you are on the brink, you have no hope, but for some strange reason you are still reading. Is there anything that can make you feel worse than you do right now? I hope so...
Follow the three day rule. If you are ready to commit suicide, like really, really ready, wait three days, or better still a week, until you actually go through with it. If you are going to be dead for the rest of time, what's another few days wait? It may be that in a few days your enthusiasm to go through with it might not be the same, which will suggest that maybe suicide is not the only answer, and possibly something could change in your life circumstances, or how you view/feel about your life, that will change your decision.
Many suicides and attempted suicides are done on impulse, but this suggests that the same people would not have tried to kill themselves either days before, or days after, had they thought about their actions for longer. Suicide is a permanent solution to an often temporary problem. It is not a decision that should be rushed.
Speak to someone. Now. People who are suicidal are very often feeling lonely, isolated, depressed, hopeless. I understand that in that place you may not want to speak to anyone. I certainly didn't. After all, what difference can they make? Or maybe you are too embarrassed or ashamed to talk to anyone about how you are feeling, especially someone that knows you? I certainly was.
But I'll say this. However much you might not want to speak to someone, do it anyway. If you are going to spend the rest of time dead, what difference making a phone call now? Speaking to someone, and discussing how you feel, is possibly the single most powerful thing you can do right now. You don't have to speak to someone that knows you. Whatever the time of day, the organisations below have trained people available who will listen to you, without judgement. If you can't face speaking to someone, see further down this page for chat forums:
US: www.samaritansnyc.org (212) 673-3000
UK: www.samaritans.org 08457 90 90 90 (Republic of Ireland 1850 60 90 90)
Australia: www.lifeline.org.au 13 11 14
Worldwide www.befrienders.org (phone numbers dependent on country of residence)
If you have a friend or a family member you can trust to listen to you, without being angry or judgemental, consider using them as well as, or instead of, the above. Just chatting to someone who cares can make all the difference. Really, it can. Even just going round to a friend or family member whose company you enjoy can make a huge difference.
Or call a minster or rabbi. If you are already having psychotherapy, you should tell your psychotherapist.It is also highly advisable to tell your doctor, as they should be able to point you towards some form of treatment (and see Addressing the problem).
If you don't want to speak to a real person, another option might be going to a chat room (see Chat), which should be an environment where you can share how you feel, and be supported by others who will understand exactly what you are going through. It is open 24/7, and some people might feel more comfortable communicating by chat than to a person. However, this is probably worse than actually speaking to someone.
Realise that statistics show the vast majority of people who are suicidal do not go through with it. You are not alone. And the odds of you getting though this and feeling better again are in your favour. So even if you think there is no hope, the statistics would point to there being lots of hope. Most people who are suicidal go on to lead a much longer life.
Think, very, very carefully, about the pain of killing yourself. Many people mistakenly assume that suicide is painless. In many cases though, suicide is not painless, and is positively very painful. Look through this site to see the possible dangers of whatever method you are considering.
To read more about longer term initiatives to help you feel better, read the section Addressing the problem.
You might also want to have a look round the Mentanoia website which also has helpful advice and guidance.