I’m sorry you’ve had these hurts and disappointments. I’ve had some similar, big ones like yours, too.
You may be putting out cynical vibes and scaring off new people, who are possibly better, more loyal, trustworthy people. My suggestion is to suppress your cynicism to new people or else it becomes a self fulfilling prophecy.
I count my blessings for the several close people who have not (yet?) devastated me. Maybe they will remain true. I will be good to them.
I was good to the ones who hurt me. I assume you have been a good person, too. So then logically, you can’t say everyone is bad, right?
I don’t know the reason why, no matter how we were loving, those people truly were not.

I just accept there’s some reason I do not understand. Like maybe had I not been hurt, I’d not be typing this message to you, yada yada yada.