A wall keeps everybody out. A boundary just tells people where the door is.

Shutting everyone out and setting a limit can look similar from a distance, but they do opposite things. A wall protects you by making you unreachable, which means nobody good gets through either. A limit is information: here is when I answer, here is what I will not do, here is how this works with me.

If you went quiet on everybody after one person hurt you, that makes sense, and it is also costing you. Pick one person you actually trust and tell them the specific thing instead of disappearing. Clear rules keep people around. Silence just clears the room.