Do you think it's selfish to tell friends when you are feeling suicidal/depressed

No, but then you can't expect them all to understand it.
If you are feeling suicidal you really need to talk to someone neutral.
If you are in the US you can call:1-800-273-8255 it is the National Suicide Prevention number they have a website as well: https://suicidepreventionlifeline.org/

I think you ought to at least talk about it if it is bothering you. Men have a higher suicide rate because they try to bottle everything up, just be careful.

if they are your friend they would want to know.. and you have to reach out to someone

No. Because a problem shared is a problem halved. It would be selfish for them to refuse to offer you help in such a situation. Friends are meant to be there for each other, not just when it suits them.

Rationally I know it's not and that they want to help. But nothing about depression and anxiety is rational.

Tell them. Let them help you. It's what friends so.

I feel that way all the time...and no it's not. I wish I had the courage to talk about that stuff with people.

I understand what you mean. I'm having a rough time too, but I'm not really telling anyone.

I keep those things to myself. Friends already have a lot to deal with, I just post it on SW. 🤷

I mostly keep it to myself.

You should tell at least one friend

what is the to be depressed about you have friends

When I'm the one feeling depressed, I sometimes think so. But when I'm the friend, I really want to know, and I want to help if I can. Let your friends help you and be there for you.