"Let them" is not about giving up. It is about giving up the exhausting need to control people, force outcomes, or chase acceptance. The more you try to make others understand, stay, or change, the more peace you lose.
Some people will leave, misunderstand you, judge you, or overlook your value. Let them. Protect your energy and keep walking your path. What is truly meant for you will not require you to betray yourself to keep it. Freedom begins the moment you stop chasing and start choosing peace.