a person who does not share her (his) troubles with anyone

This situation makes you an example of many things, is your secret safe when you break up with the person you are talking about? It will certainly protect you from such things, but the situation in question is psychologically very inconvenient. If you didn't share it with anyone under the carpet, it will bring the dust to the surface again.

Advice: My humble advice is that even if you have had bad experiences from people before, do not give up on trusting people, because if you cannot do this, you should definitely tell a psychologist about your troubles and problems.