Been out of love with my wife for almost a year , how do you know when to call it quits ?

Married 6 years , have a 2 year old and a 6 month old. Was in a long distance relationship ONLY with my spouse before we got married. I am on parental leave from work until January. Feels like I am a housecleaner , errand boy , babysitter , cook , cleaner , slave etc... but not a husband. I resent her very much and I am tired of living this way... She denies there's any problem and scoots around my idea of marriage counciling. Any suggestions are appreciated.