Tamar Braxton's Marriage Crumbled After 'The Real' Firing

Tamar Braxton was depressed for months after she was fired from "The Real" ... and it wreaked havoc on her marriage that ultimately failed.

Sources close to Tamar tell TMZ ... the singer's marriage to estranged hubby Vince Herbert suffered an irreparable fracture after going through a time of depression stemming from her firing in May.

While they're no strangers to a roller coaster of a relationship, we're told losing the gig created bigger issues because it compounded an already teetering relationship. And one of the first steps to get back on track -- moving out 3 months ago, even though they acted like a couple just 2 weeks ago.

Our sources say Tamar and Vince put on an act in NYC as an engaging couple simply to promote their show. At this point, we're told Tamar had already moved in to a baller high-rise.

Her 2-bedroom luxury condo in Bev Hills goes for around $15k a month. Some of the building's amenities include an indoor 75-foot lap pool, an outdoor pool as well, 5 gyms, a spa, a restaurant with free bar, a screening room ... seriously, there are more amenities than any building in America.

That's how you bounce back.