...let's start with the obvious. If you're here reading this post then you survived one day - most likely your worst day. You know every day will have ups and down but they will trend better and better if you do one thing - focus on moving on and not looking back. Also, you're in your mid-30's so unless you are extremely overweight or have a serious health issue the chest pains are probably a 99.9% chance of being stressed.
Your history. Three LTR's isn't so bad. This brings another question. Were all of the back to back with little or no alone/single time in between? If so, then we'll know a bit more to help you out. If not, don't sweat this part.
Her history. From what little you've said she's still basically stuck in a very juvenile understanding of relationships because she's never been out of one long enough to understand what it really means. And she's pretty young - great for dating but maybe a bit too young to be so serious with. BTW, congrats on pulling a younger woman (unfortunately just not a good one for you). Most guys your age start chasing 42yr olds because it's easier.
This wasn't a LDR (long distance relationship) so that's good. And no kids is even better since this is over and one with.
Despite what another poster said, women swing branches in more countries than just ours. However, if you need to work out some anger by all means get angry - just take it out in a healthy way.
From what I can tell she was the prize and owned the frame in your relationship. When you look at it from the outside you being in your 30's and her in her 20's that almost seems comical (but it's not). As you get into your 30's your knowledge of women should be increasing and you'll find yourself starting to have this dull indifference towards them - especially their actions. You mentioned her being detached and withdrawn and you wanting to be closer. Duh - she had the power in your relationship and when she started removing the prize you instinctively want to get it back again.
It sounds like you have committed to this being over and done with. Can you take the next step - with no kids and no common living arrangements can you completely move on. Zero contact. Never again.
Then do as the other guys are saying - get busy, work out, eat right, do guy sh!t. I'll add to that - unplug your TV (I don't give a crap if it's a 60" Flat Screen). Then unplug from all the BS around you. Start doing things (again if you had given them up). Get outside everyday even if it's crappy out. Without walls around you some of the stress has a way out. Meet new people. Start learning why you missed all the red flags. Try to figure out why you are so focused on being in a relationship. Get some good books (self help or whatever). Ask lots of questions here but do me a favor and try to focus on questions that will help you rather than dissect her.
And yes, you did come to right place. If you can be honest with the guys here they will help you through this and help you unplug for good. You'll learn in time that women are not evil or devious they're just being women and acting like women have for 1000's of years. It's us who miss the signals, tests and signs it's over. Then we get frustrated that they didn't just tell us (us expecting them to be like us!).
ps. KX's post on how things end for women and branching swinging is excellent. Read again if you have to to match up the warning signs you missed so that won't miss them again in the future.
