take a bulldozer and dig a big trench line in the sand....
YOU HAVE TO SET BOUNDARIES for YOURSELF and for your CHILDREN.

i had the i love you (want you back) to the i hate you (get out of my life) to the i love you (i want you back) and
everytime i went back WITHOUT boundaries.....NOT that boundaries is a guarantee for anything....but i went
back over and over and over WITHOUT boundaries....well toots....we are not together and he took HUGE revenge on me and hurt me deeply.

so set them, stick to them and don't feel bad about being harsh!!!!