Not sure you actually WANT THE TRUTH AS *I* SEE IT...
She's NOT coming back! She's not interested in being engaged to you, or marrying you, or living with you.
we were not married but engaged, been together for 4.5 yrs...this heavy relationship was too much too soon for her
I don't know how 4.5 years could possibly be considered "too soon".
Absolutely an 'age thing'; she's as close to 21 as you are to 40! Although I'm sure it made her feel mature to land an older man, what did you two REALLY have in common? She wants to be young and wild and hang out with her girlfriends, flirt with cute guys, be a young 20-something. Can hardly blame her for that.
when she used to go out she wouldnt let me know where she was or when she was comming home she would ignore me alot
Yeah, cuz she was busy flirting and having fun with guys HER AGE; she knew you wouldn't approve.
Look, you provided security. She didn't have to live at home, yet you gave her a better place to live than she could have afforded on her own or with other young people with cr*ppy jobs. You gave her a car (thus allowing her to save more of her own money), paid the bills. She could just be a princess and spend her money on stupid frivolous things. You were a convenient guy who paid the bills, and she liked you well enough, but you were NEVER gonna compete with the hot 20-somethings she and her girlfriends are meeting at the bars.
Not really. She's decided she'd rather live in lousier surroundings, NOT have to clean up around the house (or listen to complaining if she doesn't clean), AND get to hang out with/sleep with hot dudes her age that she meets at the bars. The positives of having the bills paid and having a steady older boyfriend/fiance have been outweighed by the freedom to hang with girlfriends and the freedom to meet guys. If this is true (and I'm a 50-something woman, so I think I know whereof I speak), then better you and she find out NOW rather than after you're married.
But hey, maybe I'm all wrong and she'll come back to you for something other than financial security. If so, avoid the begging and pleading - it will cause her to lose respect for you.