I'm working on that problem myself. It sure isn't easy especially after one is betrayed over and over again.

Cognitive Psychology has a theory. According to this theory, we are most often hurt not by the events in our lives but by our expectations about ourselves, others and events.

An expectation is a very odd sort of thing. It is stronger than a wish but almost as strong as a demand. Expectations comes in two types: realistic and unrealistic. Unrealistic expectations can cause a lot of unnecessary aggravation, frustration, anger and sadness according to the theory.

If I, say, I "expect" drivers on the road to be careful and polite and fair, I am going to be in for a lot of disappointment and these engender anger and sadness and hopelessness.

It isn't that drivers on the road are "making" me angry and sad. It is my expectations about drivers on the road which is leading me to these feelings. To expect, or worse, demand that people be a certain way is unrealistic. It is an unrealistic expectation according to cognitive psychology.

A "wish" is softer than an expectation and a frustrated wish generally leads to less pain than a frustrated expectation or demand. If I wish the people driving on the roads were more empathetic, fair, careful and then my wish doesn't come true, it is not so devastating as if I expect that.

One cannot control others, so the theory goes. At most one might be able to influence them and that not even all the time.
Although one cannot change the whole world, according to cognitive theory, one might be able to change one's expectations about the world for the sake of reducing one's pain and distress. One way to do so, is to lower one's expectations to make them more realistic.

According to cognitive psychology, it is of course true that one doesn't have to lower one's expectations or even demands. But at the same time, if one doesn't lower them, one cannot really be free of unnecessary pain and unhappiness. One has to choose.

I have been betrayed more times that I can remember. But I have only met x number of people on the earth and there are literally trillions of people out there.

While no one is going to be perfect, there are going to be differences in the trustworthiness of people, some being more, some being less trustworthy. Cognitive psychology says that it is unrealistic to say that all those trillions of people are equally untrustworthy. That is an overgeneralization.

So for cognitive psychology, the best one can do is try to find more trustworthy people than one has already encountered and to lower one's expectations, not for the sake of lowering them, but for the sake of lowering one's pain and distress.

There are a certain number of people who are going to betray one's trust in a big way. One can wish it wasn't so, but one cannot expect it not to be so.

So the theory goes . . . Some people have been helped by this theory. I am one of them. It is not a perfect solution. There are, of course, no perfect solutions since no human being is all-knowing, all-seeing, all-powerful and all-perfect. Those attributes are not possible to finite beings and every human being is finite.

A friend I knew was a perfectionist. He "expected" perfection. I think he was raised that way.

He was pretty unhappy and angry most of the time. His shoelace broke and he cussed up a storm. Someone cut him off on the highway and he went ballistic. If the line at the checkout counter at Walmart was too long, he exploded.

He was pretty miserable. According to cognitive psychology, it wasn't the world making him miserable, it was his unrealistic expectations about the world that made him miserable.

Sadly, my friend passed away at a young age after suffering a cardiac event. If he could have been able to perhaps lower his expectations a bit or turn some of them into wishes, perhaps he would have been happier and more at peace about things. I don't know. People are so mysterious.

I am trying to trust people again using some of the things I learned from cognitive psychology. It is no picnic. Not sure I will ever be completely free of my fears and worries although I think I am doing a bit better than before.

I sure hope you find something helps you. And I hope you find someone who will not be so bad to you as the people in your past were!!!