[Hennah]

In other words, how to better prevent people from taking advantage of my goodwill? I've gone through a very long school of hard knocks about this, learned to be more assertive and critical before trusting. As a youngster I resorted to excessive critical approach to others and it led to me over-analyzing motives of people, being on guard in every social occasion unless alone. It has become very draining mindset however.
Forgiving and letting go then again feels that I'm suspectible to these opportunists. I've sometimes still allowed them to take what I no longer need, but it eats up my self-confidence... while trying to become just like them to better understand the behavior and counter it goes against my core values... even if my root motive for doing it was "good" (to protect what's yours, not to harm someone to benefit yourself) and therefore excusable.

Finding new trustworthy people to surround myself with is hard because of this too.

How should I approach the problem?