I get it, you are trying to exaggerate how hard something is, how tired you are, or how much you don't want to do something so you decide to talk about how you are going to kill yourself; life sucks. But, do you really need to make a joke about killing yourself?
Just think for a second. Think about the awful words and jokes you are making and consider how others may feel when hearing those words. Have you ever thought that maybe instead of saying something like that you could just say "I really don't want to do that" or "I'm just so tired" or "If that happens I'm going to be so disappointed."
There are so many people in our world today that suffer from suicidal thoughts or have lost someone to suicide. It's a real problem in our world today and we need to stop making jokes about it. Think about all the people that have to hear that and have lost someone so important to them or suffer themselves. They shouldn't have to listen to people making jokes about death. Our society today doesn't take this seriously enough.
Every time I hear the words "I'm gonna kill myself" or "I'll just shoot myself" my heart drops. Every time I hear those words I go back to the day I stood at my brother's memorial services honoring the wonderful 21 years he lived, but ended so quickly because of suicide. I shouldn't have to listen to joke after joke about suicide. I am already reminded every day that my brother isn't here, I don't need to listen to you make a joke about he passed.
Stop making jokes about something that should be taken extremely seriously.
Life is so precious and can be taken away in the blink of an eye. Tell everyone that you love them and how much they mean to you. Stop making jokes and please change your damn vocabulary.