I'm secretly suicidal and really depressed but I don't know what to do or who to tell so I keep it hidden.
That must be hard to deal with alone. Isn't there anyone you can tell this to?
Not really, but my friend is very nice and I really like him
That stinks that you feel so negative like this. Just understand that if you are able to breakthrough and reveal what you are bottling up, you will literally immediately feel better afterwards.
I don't want my friend to worry and I don't want people to know. I might do it anyway.
Do not kill yourself. There is so much hope for you and there are people that can help you that will allow you to understand that.