“When you're in jail, a good friend will be trying to bail you out. A best friend will be in the cell next to you saying, 'Damn, that was fun'.”~~Groucho
There's some good people in the world but also a lot of users and often you can't tell the difference until it is too late. So you either isolate yourself or take that risk. I've had periods of my life, decades that were pretty damned fun but also some hard times. I'm just working to get out of one now. And friends that fuck you over make the hard times even tougher. You'd be surprised at what shakes out when things shake up.
The good time girls are first to fall out of the tree. When your life is going well, they're there "for you". When their life gets tough they are most certainly there for you to help them through their shit but when your life gets rough they disappear and then people will make excuses for them: Oh, they weren't able to handle that. They could only do so much. They're not that strong.
What a fucking crock.
These are the times when people show their true colors. Or even if you had seen their colors but thought you could work with that, then these are when those colors turn to shit.
I have finally found the best way to handle this. On becoming a friend with someone new, insist on a $10,000 deposit for your friendship. That way, if they remain your friend throughout your life, you can will the money back to them or their estate. But if they fuck you during that time, then you keep their money as a fee for professional services rendered. That way you won't have to go through the rest of your life feeling so damned used by them. I think that just might work.
As a bonus, that will keep them from fucking over too many other people because in this economy how many extra 10k could they possibly have. So your charging for your friendship is a benefit to the world. qed
(on the other hand, if this is about your parents not helping when you think they should, it could just be they are teaching you to stand on your own)