When is it finally ok to walk away?

 Just like that, it all changes again. 

At what point in a relationship do you get to say enough is enough with out the guilt of walking away.  No i am not talking about my husband and I, but another relationship that is supposed to be unconditional. 

My mother and I.

So many times i have dreamed of a normal relationship, but i will never have that and i guess it is now something i have to accept that i will never again even have a relationship with her at all.   She has always done things my whole life to go against me or to hurt me and every time i say "she is my mother"  and i go back to her to help.   Well why cant there be a time when i can walk away and feel no guilt??  I have given my all.  Time and time again i have forgiven her and tried to rebuild and again and again i get hurt in the end.  

This time, I know in my heart i gave 100%  and she again destroyed us.  I can walk away with out guilt......or so I hope.