Suidcide is haram (forbiden), and it is considered as one of the greatest sins in Islam. A person who commits suicide, according to multiple narrations from the Prophet (pbuh) and the imams, will enter hell fire, even if he/she is a muslim.
There are several reasons why suicide is haram.
First of all, it's because we are not the owners of our owen life. We didin't give life to ourselves. It's God Almighty who gave life to us, and it is Allah who is the owner of our life. Therefore, it is only Allah who can take away our life.
Secondly, I am only allowed to destroy something, if I have made it myself. For example, if I make a painting, then I am the owner of that painting, and I have the right to destroy it. Nobody can blame me if I destroy the painting which I made by myself and belongs to me. But, if I destroy the painting that belongs to somebody else without his/her permission, then I have committed a crime. In other words, if I don't make something, then I have no right to destroy it. And, of course, I didn't make my own life, and Allah made it, so I have no right to destroy it.
Third reason why suicide is haram is because Allah has told us in Qur'an that we should not kill ourselves. When our Creator tells us that we should not do something, then we should listen and follow our Creator.
Fourth reason is that people commit suicide because they are unhappy with their life. For example, they suffer from hardship or physical pain or psychological pain. But, Allah has said in Qur'an that this life comes with hardship and difficulties, and we must have perseverance and have patience and put our trust in our Creator. We must consider every hardship as a test or as an exam in our life. And every time we experience hardship and difficulty we should say "alhamdulillah" (thank Allah) and ask Allah for help. With every hardship, after we live through it, we grow stronger, and we achieve a higher level in our life. Of course, we should also try to remove the hardship. For example, if it's a physical pain, we should go to a doctor. If it's a psychological pain, we should receive consultation from experts. If it's an emotional pain, we should discuss it with close friends or relatives, etc.
Sister, right now our brothers and sisters in Gaza are going throught extreme hardship. Their children or their parents are being killed. They have little or no food and water. Their homes are being destoryed. But, every time we see them they say "alhamdulillah." These are the true belivers, and these are the people who will enter paradise and will receive the best of rewards (which we cannot even imagine) from Allah for their perseverance and for their patience.
One of the members of our club has asked the following question by private message:
"Why is it haram to sucicide and what happens if you do it?"