HOW do I stop resenting my girlfriend?

The problem lies with household chores. I have talked to her about this on numerous occasions, but it always results in an argument. Basically, although she does put the washing machine on, cooks and washes the dishes occasionally, I seem to be doing 95% of the cooking, certainly every weekday, and more often than not at the weekends, and doing the dishes 95% of the time, thought admittedly she does do them once at the weekends, sometimes twice. I really do not want the type of relationship of my parents, where my mother does almost everything. But I would like a bit more help, as I’m beginning to feel that I’m here to tidy up her mess (and she really is messy), make the bed, cook and clean for her and generally play the role of her mother. She says she’s too tired after work to do anything, so everyday I prepare her meal and clean up afterwards. Maybe I am completely in the wrong, but my resentment is beginning to make me feel really unwell, and with a lot of suppressed anger. HELP!!!