"we are going to die so why prolong the inevitable"
This might be a very silly example, and I am not underestimating the seriousness of what you have said. The book will come to an end so why bother reading it? Our friends are going to die so why bother getting close to them? Yes, all things begin and all things end but it's what you do in the middle of that that's important. No one knows when they are going to die unless they choose the date themselves. No one knows what is around the corner. Yes, there may be something bad around the corner but there also could be something so fantastic that makes life worth living. Perhaps when you are dead you won't remember all of the good things in your life but at the time it's worth experiencing them. The end isn't important, really. Even when we have achieved a goal often the best part of that is the process. I can really understand where you are coming fom and it can be easy to get caught up in the fact that we will all die but there are so many things that come before death.
"its my life and therefore I can choose when my time is up"
I guess that's right to a certain extent but you might decide that your time is up and something intervenes. You can't control for the actions of other people or the way your body responds to an attempt to take your life. There is no guarantee that when you decide that your time is up it will definitely be up. It could even make things worse for you if you become seriously ill and perhaps aren't able to make any decisions for yourself because you are so ill. That would be worse than having autonomy while living. We all think that we have made the right decision sometimes and later on realise that it was actually the wrong one. Death is so final that you can't go back on that decision. There are in-between decisions that you can make. You can decide that your time of living in this way is up and look for other ways to live your life in a way that is more satisfying for you.
This is something that I myself think quite a lot of the time, but life is only meaningless because you yourself can't find the meaning right now. It takes time to work out what your purpose in life is. I'm sure that there is personal meaning out there because there are so many people who continue to live and enjoy living. It's just a matter of finding that purpose. There is so much that you can do for yourself, other people, and the world. No matter what you do with your life you are giving something. You are a friend, if yo have a job you are giving to society...all of those things provide life with meaning.
I can understand how difficult it must be to think positively and think of a future while these things are continually in your thoughts. It can really help to challenge them and bring some positive control into your life. You're right, there is no other way out of life than to end it (or wait for it to end itself) but there are ways out of this pattern of living that you are in. Look at your dreams, set yourself goals, make changes. By not self harming last night you have already exercised your control and proved to yourself that you do have control over some things. Use that control in other areas of your life. If you need support through this please talk to your doctor, phone a helpline, or get in touch with the supporters.
I'm thinking about you, please take care.
