Confused, and hurt

So in relationship with a woman for 5 years, for the last year and a half she got distant and changed .I am 12 years older.we have an amazing intimate life.she lies constantly, over stupid stuff and real stuff.says nothing is wrong but doesn't reply like before.leaves my text on read . recently said was going away for the weekend with family.but was not there. All the red flags are there. But I am so in love with her. I know I need to leave. But I just don't know how to do it. It's so painful. I know what I need to do. But instead I suffer. I communicate my feelings. Doesn't seem like she cares. Being hard broken really stinks.