yes it has, I've had my heart broken just ONCE, i felt like dying, i cried every day almost without stopping, and the thought of that person could send me spiraling into suicidal thoughts and give me physical pain that i couldn't stop. It was enough to make me realize that as much as i want love and closeness and to grow old with someone whom i love with all my heart, i have tried since then not to feel as in love with anyone as i was with that person. Whenever someone promises that they wont hurt me, that they'll never leave me, and that i am their world, all I can think is "yeah, they said that too but that didn't stop them from hurting me". So when it comes to dealing with people, or certain types of people, I try not to get involved, or i don't let them know how much i feel for them so that maybe they would feel as scared of losing me as i do them.
Being cheated on and trust is very fragile.