Why cant i tell anyone?

For the past three years iv been super depressed and attempted suicide twice, thought about it probably about 20 times. Nobody knows whats going on, smiling is easier then expressing the pain. Lately its been getting to close, these thoughts are tearing me in two and a few days ago i almost did it. I was all set to make it my last night, i wrote about why i was doing it. I kept thinking if i cant love myself then nobody can. I got a sharp object and almost did it but heard my mom get up in the middle of the nght, seeing my light on she came in. By the time she had opened my door id hid the note and object. She asked what was wrong but i just said i was tired i couldnt tell her what was going on.. later that week i tried again but i just couldnt do it in fear someone would find me before i was dead and id damage myself permenently. today is the day, its my last day. im eather going threw with it, or telling her everything. i just dont know how to tell her.. What do u tell your mom when you have been trying to kill yourself the past 3 years?