Wall

I build wall around myself so i don't get hurt,
I let them crumble for those who i think will stay,
What i don't know is that every single one of them has a knife.
They stab me with it over and over.
The ones i thought would help are the ones who end up hurting me the most.
The open wounds start to hurt once they disappear.
I feel their their memory stab me,
As I restart to build another wall...