I'll try to keep this as short as possible, but it's complicated. Some of you are not going to like some of what you hear, but I already realize my flaws.

Was married for 15 years. The last 2 or 3 really went downhill to the point I just didn't want to be there anymore. Met a girl and started seeing her. Yes... I know (not cool by me doing it that way). Anyway, we end up falling MADLY in love with each other. End up moving in together, planning out lives together etc...

In the meantime I was still legally married. My wife moved on and lived with our 3 sons with someone else. It was a little problem with my girlfriend the fact that I was still legally married. However as time went on it really became a non issue. It was as if we were separated.

By the way I'm 40 she's 27. My GF met my kids, parent, etc.. Everything was cool. There was at first a slight issue as to her being young and acquiring me with the kids, but as time went on she became a part of it.

We really had fun together and got along great. Out of the blue (we had a mini kind of fight for a few days) she broke it off with me after 4 years! I gave up my life for her and she told me she wanted me forever. I left one morning kind of not speaking to each other. She packed my stuff and told me she didn't want this relationship anymore. Said it's not what she wants. Second guessing being 27 and taking it all on, not knowing what she wants to do with her life. Littereally first time I ever remember even fighting. Her mother talked to me and tells me she loves me still but just looking at her future.

Here's the thing. Needless to say I am a complete mess. I love this girl more than anything. And I know she loves me. We were everything to each other. So... before doing some research on how to handle it, I... welll went a little nuts texting her begging, do anything in the world, trying to make her think about it logically. Everything you're not supposed to do (for about a week).

Then I learned about this NC thing. My question is, am I done? Have I pushed her too far to never come back? Kick myself in the rear every second now and wished I never contacted her at all since she broke up with me. I really think she's making a mistake.. Nobody will make her happier than me. And I really am having a hard time with the whole thing. I can't eat... I puke, I can't sleep, I can hardly get through a day of work. I sit here wondering how and why and litteraly walking in circles. And it's not getting any better.

Also, she acts as if it doesn't even phase her. Emotionless.. almost mad. Last thing she said was stop nothing will change my mind it's the right decision and what I'm doing. How can it be humanely possible to flick the switch? Does she not miss me at all? Not reflect on all the good memories and times? Really don't get it.

Anyone?

So... you walk out on your wife of 15 years and then when your new love ditches you without remorse or care, you don't understand how she can? 'How can it be humanely possible to flick the switch?' It happens every day. You did it yourself!
It's happened to just about all of us. It hurts, it's pain beyond belief.
It boggles my mind that you think you are alone in this, and it always boggles my mind when someone says 'Nobody will make her happier than me.' How egocentric is that?
I'm not unsympathetic, but really now.
Plus... I don't suppose that you might have considered that at 27, she's thinking all those thoughts most women think when they approach 30: marriage and children. And there you are, still married with children.

Joy,
I understand where you're coming from I really do. The difference is when I left my wife we were done! I didn't wake up one day and leave. It was years leading up to it. No communication, didn't do anything, different goals, stopped being friends well before I left. There was nothing left.

The months, weeks, days leading up to my GF breaking up with me were probably the best we had. We laughed together, talked about our days at work, go out to dinner, watch movies, cuddle on couch. We were best friends.

So while I do understand what you're saying, I still don't see under those circumstances you just flip the switch without any feelings. And to be honest after I left my wife and to this day I do still think about her and miss her.

OK, I hear you, but still, it happens every day. Sometimes it's a sign that another love interest has entered the picture.
When people come here to ask questions, it's best to ask ones that relate to their own feelings, not someone else's. Asking 'why could she be so unfeeling' is pretty much rhetorical. We don't know her and she isn't here. So the answer is: because it can be done, because it's human nature. Any more than that, who knows.
And you haven't addressed my other two points about you believing you are the best thing she'll ever have, and her clock ticking while you stay married. So I'm starting to wonder if you are stuck on wounded pride and not listening or thinking or even wanting to understand her.

Best thing that she'll ever have was not meant as egotistical in the sense that I think I'm the greatest thing out there for women. I meant it more as I would devote every single day of my life to make her happy. We already have a better foundation than most relationships I know of. If I/we took it up a little more I don't see how it could be better with anyone else. There's companionship, friendship, sense of humor, genuine like and love with us.

I do understand the clock ticking you're referring to. And to be honest that's probably what it is. But my ex has been living with another guy for 3 years. It was never really brought up as to when I'm going to make it official with her. It didn't seem to matter. She wasn't really in the mix of things so to speak. And my GF knows the second she said she needs it to be done to move on, I was at my lawyers the next minute.

If you haven't done so already, get a divorce, a legal one. Then you need to respect this young girl's decision and move on. Be alone for a while, you used her as a scapegoat from your marriage and she has finally felt it that way. Take it as karma, you ended a 15 year old relationship, she ended a 4 one with you... at least it didn't take as long, it would have only made things worse for you. Keep busy, go no contact, take care of your children, and move on.

I still think you aren't getting it. 'I would devote every single day of my life to make her happy' is one sided. You are speaking only for yourself. It isn't what SHE wants anymore.
'If I/we took it up a little more' is also one sided. And it's all based on IF! You didn't. You didn't follow through on your divorce, claiming that she didn't care. How do we know she didn't care? Maybe she was too proud to nag about it.
And now it's too late to redo the past. You should have worked on all this over the 4 years you had her.
Send her a letter (on paper, not email) if you think you have the eloquence to tell her you will pitch a tent outside your lawyer's office, marry and start a family with her in a heartbeat if she will take you back.