What should I message my friend? I just want to be there for him like he is for me always.

My friend recently changed his username to “feeling super super sewer slider (aka km*) and his profile picture says “ I just wanna kil myself”. As his friend me and his friends always tell him to stop saying that he’s ok. He told me personally, that he doesn’t want me to worry about him simply because “there is nothing to worry about” and I told him I couldn’t stop worrying constantly asking if he’s ok and he says “yes” he told me “do we need to have that lecture again? I’m fine” he constantly helps everyone he can and he is such a sweet and caring guy and when I vent to him he always helps me but I’m scared to ask him. He told me “I’m a piece of ****. I’m not diagnosed with depressn and you probably get mad when I say I’m dpressd and sad all the time”. He’s very insecure and always talks trash about himself. I’m really worried about his health and I’m not sure what to do.