There is a lesson I learned rather recently that helped put a feather into a similar storm of my past, namely "Maybe you do not miss the person or place, but rather you miss the feelings you had at the time."
Not all connections work out, and many places are rearview towns. Whether you did any wrong is irrelevant, you decided, and YOU are the one who gets to decide, to leave. And if they have a hard time accepting that you left, that is on them to figure out, not for you to fret over.
Let them talk and say what they will. You took your life and made a choice to go a path you felt was right. All that matters.
There is no magic bullet to moving on, I would be a liar if I said otherwise. But it does help to contextualize. It does not have to be "everything was bad," or "everything was good." It was an experience, what seems like a not very healthy and quite complicated one, but an experience nonetheless. It serves to help teach you lessons about yourself, about others, and about how you view and interact. Talking about it is a great first step, it means that the turmoil is not getting locked in a cage, avoiding light to shine into it.