I'm pretty introverted and generally dislike (in a passive this person will probably not be a new close friend type of way) most people I meet. I've still managed to develop a handful of close relationships over the years. Even the ones I fucked up I can still reach out to and get a response if I need it.

Will everyone of them always be able to be there for me? No. But I'm not always there for all of them. My brothers about the only one I assume I could talk to about anything anytime. But just because other are not available to me during tough times doesnt mean I don't have a close relationship with them.