advice pls

i don't know where to ask this, so I'll just ask here, i guess?? tw: mentions of suicidal thoughts

i have this friend that's very depressed and suicidal.. he is always talking bad about himself and about how he wants to kill himself. it doesn't matter what i say to him, he'll always try to argue about why dying is the answer to his problems, and everytime, i end up getting pulled down into that kind of thinking too. it's very difficult to just talk to him because he always twists it into something negative.. I'm trying to help him, but it's difficult for me because when he talks about suicide and death, i always get those thoughts too.. i also struggle with depression/suicidal thoughts/anxiety/etc, so i know it's difficult for him, but i can't take being pulled down by him when we talk.. I'm really struggling.. i don't know what i should do. i don't want to hurt his feelings by stopping myself from talking to him since he's always saying that nobody ever stays with him and always leaves him

i said he could talk to me about what he goes through, but i don't know if i can handle it anymore.. this might just be selfish of me, but he really puts a damper on the mental health I'm trying to maintain for myself.. what should i do?

(sorry this got so long..)