There are many people looking for their loved ones out there.
Everybody expects to find someone and to be happy with, but no one should rush things up.
It feels as if we need to catch a significant other before someone snatches them away first. (?)
When you think in those terms, you might end up dating someone just because you don't want to be alone. If that happens, it may lead to a bad relationship, in the hopes love will be born over time.
That's why people cheat on their partners, because they didn't have the patience to wait for the right person.
It might be your perception but the matter of cheating can be way more complex than that, it´s difficult to pinpoint a definite cause, every case is a case.
But don’t give in to the pressure to marry if you haven’t yet found the right person, as if you don´t you are in some way defective.
Don’t believe that you’re unworthy if marriage didn´t work out, even if you thought it was going last forever.
You are saying that someone has "left", one way or the other you are citing the other party here. Plus the reasoning was winding, first from the reason for cheating, the rush to marry, and now that the one party decided to leave. One more thing, today the notion of marriage is about love, fulfillment, partnership and even other motivation, but the possessive "your/s" may suggest something else.