Healing is not divisive, what caused it is divisive. Do what you need to do to protect yourself and do not let anyone tell you that healing is divisive.
Needing space or some level of distance (if not full distance) is actually a side-effect and it's quite normal when you're healing.
You don't have to prove your healing to anybody by exposing yourself to what caused you harm either. The more you heal, the less you desire to be around what caused it in the first place. You do not have to expose yourself to more trauma or retraumatized yourself to prove to anybody that you've healed as that would lack self-compassion.
Boundaries are very basic guidelines of what you will, and will not tolerate, that is not the same as a barrier. Don't let anybody get this twisted.
Caring actually begins with respecting the free will and autonomy of others over what belongs to them, intrusiveness is often mistaken as caring, but intrusiveness is actually rooted in control.
How long ago something was has nothing to do with your unique healing journey, and that's no one's business either.
Boundaries are only a problem for those who cannot use you and are mad about it. Lines are only paranoid to manipulators, you're a free agent in your life.