Marriage in trouble!!

Husband and I have been TTC for over a year. Been married for a few months and I have a 3year old stepson. We have always had stress in our relationship because of his sons mother always trying to start trouble and bringing up the past but Lately I feel like all we do is argue about everything and say hateful things to each other. I have told him several times that I am at the end of my rope and I can't take anymore but I don't think he takes me seriously. I'm tired of the crying and the hurt and the selfishness. He never takes my feelings into consideration and I don't know what to do. Should I leave for a little while and let him see what life would be like without me? Let him keep walking all over me..i need help!!