I'm not disagreeing with Karin Samms, but just adding a thought about what might be going on with her. 2 years is quite long for an engagement, and if she's been living with her family for most of her 45 years (or even if that's just a "return engagement" after a divorce), she might actually like the uncomplicated (and ungrown-up) life at "home" more than the prospect of a less certain future with you. So the "engagement" might have been more of an adventure in possibility and a symbol of her success that she could talk about, but not a real urge to move out and start a productive life as an adult. Then there's also menopause, and that could put a big question mark around sex for her, and with that make romance full of pitfalls where she could feel too vulnerable as a woman to want a man she hasn't lived with to be intimate with her.
Perhaps some of these possibilities make sense to you, and allow you more peace of mind, if you consider that she might have finally realized that marriage was a dream come too late for her. That is particularly likely, I think, because her tone with you has been so abrupt and harsh--that tone sounds like unconsciously shifting some imaginary blame onto you for HER own embarrassment of having "led you on" to expect and anticipate marriage with great excitement, when in fact she's been increasingly viewing such a future with some excitement, but even more embarrassment, vulnerability and outright dread. If she also has an aging mother and/or father that apparently needs her, then she has all the partnership she'll need, especially if sex is an uncomfortable concern during menopause.