I understand what you're going through. Last week my girlfriend with whom I have a 4 year old son told me she doesn't want to be with me anymore after 7 years together. To make matters worse she is seeing someone else.
The pain and emotional upheaval I am feeling is almost too much to bear. I am constantly oscillating between panic and depression. The future is suddenly a bleak and scary as hell prospect and I am terrified of the loneliness that lies ahead. I will be 47 this year and I'm not holding out much hope of meeting s.o. for whom I'll manage to achieve the level of love intimacy and respect I had for her.

The worst part of it all is that I had it coming. I have been emotionally unavailable for the last few years because of all the pressures of life, work, childrearing, household. Now that it's over i can't stop playing back all the moments in my head when i was neglectful and uncaring. The guilt and remorse i feel are unbearable. There is nothing worse than realizing you threw away the best thing in your life. This will haunt me for as long as I live.

To be honest i cannot see myself ever recovering from this, but that would just shift the pain to others who are undeserving of it. At the same time i have no idea how i am going to bounce back. This is by far the single most traumatic experience of my life. The world suddenly feel cold and alien and there is nothing to do but live through each horrendous moment.

My one and only comfort is scouring the net looking for posts from people who are going through the same hell. It helps to know you're not the only one.

I hope this provides you with some comfort. You are not alone.