You sound as though you actually expected people to not let you down. People will always let you down actually. Even the best, if you come to totally rely on them, will eventually let you down. It's how we are. God will not . You need a good dose of Jesus Christ and His Spirit in your heart, even then you will let yourself down. Stay in touch with the Lord, maybe He will bring someone to you who is fairly reliable, just don't expect perfection because non of us has that except in the Spirit.
It's not that it is hopeless. A lot has to do with our expectations in others. We are all flawed though. Have you been a perfect friend to someone else today yourself ? I can answer that for you, no ! Of course not, because we are all flawed. God is who you want, you can rely on Him.
We go to church because we are not perfect, to get a dose of "built up". But it doesn't last much past the front door on the way out. By the time the wheels hit the street leaving the parking lot it's 2/3 forgotten. But that 1/3 is diamonds and rubies if we can hang onto a portion of just that much, then In time maybe we are a little bit better people for it.