You can quit your relationships at any time, too. That's a fundamental tenet of our society - consent to an interaction between free people can be withdrawn at any moment for any reason.
That's not perpetual anxiety - that's the way things work today, and the way things have worked for generations. Anyone pretending otherwise is fooling themselves with lies.
Before I continue with this thread, how old are you? And have you ever been in a long time relationship with someone? Do you own a house? Have kids?