Look i can't give long term advice on preventing suicidal thoughts, but I have my own triggers and reasons that could apply to yourself if that helps? 1st of all there's thoughts of suicide when you're inconsolably sad and you just want to make the pain go away. These types are usually temporary and the pain just takes a few weeks to fade... Sometimes you feel like it's the easy alternative... That you've just dealt with so much and you're not ready to keep waking up and repeating the same life and/or you're trapped in a situation and feeling like it's either the only alternative, or it's the only one that you can cozy up to, because the other choices are to difficult for you to make a decision. There's a violent scale of absolutely despising yourself and the life that you live, usually feel like you want to cut the pain out of yourself. There's probably more, just different for everyone i guess. I think for people dealing with mental health, it's kind of the normal thing to do, to fantasise over different or exact ways of taking your own life. You're not alone and you're not weak. Being to scared to take your own life is human, you need to confide in somebody and if your nearest and dearest have no time or interest in listening to you, just crawl outside the box and ask an acquaintance for a chat.