Is it time to call it quits ?

My marriage is on its way towards break-up. I don't want to bore you with the whole story, but here is a summary. It has been 6 years for our marraige, lot of quarrels/fights from the last 5 years years I should say..Every other small issue is blown out of proportion by my wife and her anger (if I dont reconcile) will last for weeks and months. Any decision I take independently or in consultation with all members (me, my mother, wife) also leads to the same. whatever love, care support that I give her is not recognized, she grows only more demanding. I find her very dominating. We postponed starting a family because of her career. I always get anxious when she is around with the fear of every other thing leading to fight. We have tried living separately for past one year, I did not see any significant moves from her side to get together. In between she took a job to another town without even informing about her move. But when I talk to her she says she wants the marriage, but my confidence level is very low based on past experience. How do I know if she has changed ?