I am sorry you feel such emotional pain. You sound young to me though, and perhaps you do not know yet that the human brain isn't even fully developed until the person is in their mid-20s. So it is really premature to be making decisions about the length of your life when all your mental power may not be available to you yet.
Meanwhile, one thing that you can do is on purpose, consciously, look for the things that are going right in your life. The brain automatically notifies us when things go wrong, because that is a survival mechanism, alerting us when we might need to take defensive action. The brain doesn't automatically let us know everything that is going right, for one thing because there are so many of them we wouldn't get much chance to do anything else but become aware of them. Generally, the things that go right are less intense than the things that go wrong. smaller and more in number, so if we are focusing on what's wrong, it is like a glaring light that doesn't allow us to see anything else. Most things go right, and if we choose to pay attention to some of them, then we can feel grateful. It's a choice. Feeling gratitude is not compatible with feeling depression or negativity. Feeling gratitude has power to erase those things from our awareness.
All of us are living our lives one day at a time. Right now is when we have all of our personal power to change our life into what we want it to be. Maybe there are things, for one reason or another, that we can't change right now, so it is important to focus on making whatever the changes are that we can. One important change any of us can choose is to create thoughts that are positive rather than negative. Whatever we think about is what we feel, so for example, if you say to yourself, " I want a certain kind of man in my life very badly but cannot have that right now," you will feel different than if you say, "I am growing myself into the person the man of my dreams will want to be with." Just notice how each of those statements feels different (if you are willing to pay attention and notice this.) What we think makes a huge difference in how we feel. We do have control over what we think.
Some things that are going right: You have learned a language with which you are able to express yourself. You know how to type and use a computer, are aware of and able to use Yahoo Answers to connect with someone, and, at least one perfect stranger has taken your post seriously enough to give a thoughtful reply to you. So that constitutes four things going right and if you choose you can focus on them and feel grateful for them. That would be a start. Practice makes perfect: it is a skill that needs to be developed and employed consistently enough to become automatic in your life. But it takes your decision to work on practicing that skill; if you do not participate it cannot happen.
If you'd like some help to get started on counting up what is going right, an author named Louise Hay has created several references with just that in mind: https://www.amazon.com/s/ref=nb_sb_noss?...
I am most familiar with her book Heart Thoughts and recommend this to you. She will help guide your thinking. All I know to say to you is that no one instantly changes overnight, but it is a process we undertake one day at a time. It is important not to be judgmental about our efforts, but rather maintain an open mind and observe what results from our efforts. Changing your perspective to where you think positively rather than negatively will certainly help relieve you of depression and suicidal thoughts.
Lastly, you do live in a flesh and blood body, and the body requires good nutrition in order for you to feel good. So junk food, processed foods that have chemical additives, and chemical substance use are factors that will make positive change become much more difficult. Research has shown that people with depression often have a deficiency in the B vitamins, so taking a supplement of B-vitamins ought to help. In addition, you can research and consider taking 5-HTP and SAM-e as supplements as well as a good quality multivitamin. Instead of ruminating about how your life does not please you, do some research in nutrition so that you will make better choices and enable yourself to feel better in your body.
I know when you feel as awful as you are describing, it would be nice if a miracle could come along and change things, but waiting for a miracle will most likely not be as productive as trying out some of my suggestions here. I hope something I have said will be helpful to you.