Fallen Friendships : You swore you’d be best pals forever, but it went sour. And the pain is very real.

You can’t think of the person without a sickening lurch in your gut. You alternate between angrily wishing you’d never met the Judas and agonizing over what went wrong. It hurts when mutual friends bring up the person’s name, when they tell you about the fun times you weren’t invited to and wouldn’t attend even if you were.

You have all the sloppy symptoms of a broken heart.

But you don’t go to marriage counseling--you’re not married.

You don’t go to family counseling--you’re not related.

You don’t go to couples counseling--you’re not lovers.

You don’t even suggest to the person any counseling at all, lest you be thought insane.

You’re “just friends,” so there’s no one to talk to about your shattered psyche, no words like ex-lover or ex-husband to legitimize your nemesis, no socially acceptable ritual to mourn the loss of the trusted confidant you once held dear.

Friendship--in other times and places lauded as passionately as romantic love--today takes a cultural back seat to every other important relationship.

Yet despite society’s alleged nonchalance, the loss of a friend can cut more deeply than losing a lover.

“I felt totally betrayed and completely lost,” says editor Justine Kaplan, 33, of Corona del Mar, whose best friend, hurting from a Kaplan matchmaking attempt that went awry, told her that she no longer wanted to be friends. “I didn’t understand. You’re not supposed to just stop being friends with someone.

“I wanted to say, ‘What the hell is this--you’re breaking up with me?’ ”

She sighs. “With a lover, you can call them up later and say ‘let’s be friends.’ But when a friend rejects you, what’s left to do?”

Any review of the popular media yields reams of articles on how to survive the breakup of a love match, but almost none on losing a friend.

That doesn’t surprise University of South Carolina social psychologist Keith Davis, who has been researching friendship breakups for a decade.

“It’s just a cultural bias,” he says. “Researchers don’t look at it and people don’t write about it.”

He says his in-depth studies revealed two typical ways friendships end.

One is a “gradual growing apart, like where someone moves and doesn’t stay in touch,” he says. “The other is a betrayal, which in many ways feels quite similar to the experience with a lover.”

The betrayals fall into three categories: stealing one’s lover, not being there when needed and the misuse of personal things, including property and secrets.

But whatever the betrayal, Davis says, working it through can transform the friendship into something better than it was.

“About half of my subjects said they were able to successfully repair the relationships,” Davis says. “In the other half, what’s learned is that the person can’t be trusted and they don’t want to be around the person ever again.”

Not surprisingly, Davis says anger and sadness are the most common emotions felt when friendships end.

“The nature of the emotion depends a lot on the specifics of the relationship,” he says. “At the minimum you’re angry because you’ve been let down. And you become very sad because you thought you had a friend you could count on.”

Still, most people in the United States don’t really suffer over losing friends, says Gene Gordon, a Washington, D.C., psychoanalyst and clinical professor at George Washington University.

“Friendship is just not highly valued here,” he says. “Breaking up means you’re close to someone but since most people aren’t close, they don’t feel the breakup. It’s not like in places like Central America, where friendship is taken much more seriously. Here, friendships are taken very casually.”

In genuinely close friendships, Gordon says, it’s natural to feel “extremely attached and very dependent.” Therefore, breakups of those relationships are indeed traumatic.

“It’s scary and lonely and awakens all the traumas of separation we’ve ever experienced in childhood,” he says. “This doesn’t mean one is immature. Very often, it speaks paradoxically to the maturity of the adult, that the friendship was that intimate to them.”

Gordon says he doesn’t know why our culture devalues friendship.

“I don’t understand it,” he says. “There’s a great deal of value placed on independence and individuality and not a lot placed on support. People are very lonely in the United States of America.”

Not having outlets to discuss friendship’s end makes breakups all the more difficult, says Stacey J. Oliker, author of “Best Friends & Marriage” (University of California Press, 1989). “Love relationships are institutionalized and people who participate in them acknowledge the emotional investment. Friends don’t.”

Oliker says that while there have been periods when friendships were “far more romantic, when the sentiments were expressed in the language of love and adoration,” there has never been a time or culture that acknowledged the consequences of friendship’s end.

“There has never been the social institution of divorce in friendship,” she says. “So people are left without guidelines, help or advice to deal with the emotional upset.”

And the upset is real, Oliker stresses.

“There are often a lot more emotional ramifications than anticipated,” Oliker says. “But often, because the feelings and conflicts in friendships aren’t acknowledged, people don’t even realize why they’re upset. They may attribute the feelings to something else.”

Lou Cooper, 57, a retired El Segundo aerospace engineer, quietly says he isn’t sure why he ended the best friendship he ever had 10 years ago or how he really felt afterward.

But his voice becomes highly animated when he recalls the man who had been his confidant and bridge partner for two decades.

“We developed the best partnership and it was just wonderful,” he says. “I worked harder at that partnership than I did at my first marriage. He was the best friend I’ve ever had and then I just blew it.”

But it wasn’t a fight or disagreement that caused Cooper to drift away from the relationship. Rather, it happened after his friend stopped playing bridge.

“He wanted to be a marathon runner and couldn’t take the smoke-filled rooms anymore,” Cooper says. “I understood his decision. We broke up playing bridge and it wasn’t a problem.”

But after that, Cooper repeatedly turned down his friend’s invitations to come for dinner. He never saw him again.

“I don’t know why and I can’t analyze it, but I know I blew it,” he says. “I almost knew then that I was doing something I’d regret and I did regret it.” He pauses. “I didn’t know it then, but I was depressed. I felt badly that I threw away something really worthwhile. But I felt like I just couldn’t talk about it.”

So why not look his old friend up and start all over?

“I still feel embarrassed about the whole thing,” he says. “I still feel down on myself about it.”

He laughs.

“It’s not over yet. I’m not dead yet.”

When the Bond Breaks

Advice for the friend-lorn:

* Remember that it’s natural to feel sad, angry or guilty when you lose an important relationship.

* Give yourself permission and time to grieve.

* Give yourself credit for having cared enough about your friend to mourn the loss.

* Talk about your feelings. If talking to other friends doesn’t help, seek professional counseling.

* Know that as painful as it may feel now, time will help.

* When the pain subsides, keep yourself open and willing to make new friends and cherish the ones you already have.

* Remember that it’s rarely too late to forgive or ask for forgiveness.