I would say that the solution to re-trusting people is not about erasing the past but learning to put the past in a corner where we do not interfere with personal growth. There is already a saying that says: Whoever forgets his history is condemned to repeat it.
We could also include the willingness to forgive the person who hurt us, forgiveness is necessary but only for us, to free ourselves from the burden of feeling resentment towards that person and not get sick in the long term. It is not necessary to run after that person to hug him and tell him that he has already been forgiven.
And all this is not achieved overnight, but we must do our part so that this can happen.