It's not selfish, and even if it were that would be okay. It's selfish to want to live, and selfish to want to die, if no one was selfish, then no one would be alive, let alone enjoying life. You're a human, and it's human nature to want & need others, wether it's intimacy, platonic, family, humans need that emotional bond, just like how swans need a mate, and lions need a pride.
I'm selfish, l own cats and chickens, do I need them? Technically no, but I wanted cats, and chickens, which while selfish, has changed my life, for the better. Be selfish, as long as you're not taking from someone without their consent, be as selfish as you need.
A person who actually does care, would enjoy talking to you, helping you, I have a friend whose tried to kill herself multiple times, and I enjoy being able to help her every single time when she has a breakdown, knowing I can help someone, and be someone's hope, is literally priceless too me, so no, it won't be hurting a person if you vented to them (as long as it isn't like three times a day ofc)
I may not know you that well, but I hope you do find someone, or someone finds you, and someone can care for you, just as people have cared for me, and I have cared for people.
