Whitney Houston's sister-in-law Pat Houston was moments from taking her own life ... or several family members thought when they called 911 -- only to discover it was a huge misunderstanding.

TMZ has learned cops and paramedics rushed to Pat's home in Alpharetta, GA today -- after receiving calls from people close to her who thought Pat had tried to commit suicide.

Here's what happened ... hours earlier Pat had posted on her Facebook page, "Sometimes you just feel like giving up on life and its many challenges. And for the first time in my life…I’m tired…and I want to finally rest. I love you guys."

Sources tell us several family members saw the post and were immediately concerned ... they began calling and texting Pat but got no answer. Then they went to her house, found her passed out in bed next to a pill bottle ... and decided to call 911.

We're told as soon as cops arrived, Pat woke up and explained she had simply taken pain medication for her back, turned off her phone and then gone to sleep -- unaware so many people were trying to contact her.

We're told Pat informed everyone ... she was never suicidal, the Facebook post was a result of stress.

Law enforcement tells us, Pat was taken to the hospital -- as a preventative measure -- and released a short time later.

Whitney Houston's brother and sister-in-law arrived in Los Angeles yesterday to attend Clive Davis' big pre-Grammy bash ... a bash Whitney's mom called "obscene."

Whitney's mother Cissy slammed Davis' invite, saying, "I got an invitation to the party, which is the most obscene thing. I don't know why they would want me to come to the party in which she died, you know? I guess maybe he just sent me a copy for remembrance sake."

Whitney's brother Gary -- along with his wife Pat (who was also Houston's manager) -- begged to differ and flew into LAX Saturday, telling us they were going to "support Clive."

Houston was found dead in her hotel room this time last year, just hours before Davis' annual party just floors below.

Whitney Houston's daughter Bobbi Kristina has a serious drinking problem ... so say family members and close friends who tell TMZ it's gotten even worse since she finished taping her reality show ... and they fear she could die unless she does something about it.

We broke the story ... many people close to B.K. feel she has allowed some of Whitney's enablers to get heavily involved in her life ... and if Bobbi doesn't cut them out soon, she's doomed to the same fate as her mom.

Those people -- sources say -- include various individuals who knew about Whitney's problems, but didn't take action when the singer's life was spiraling out of control.

Bobbi's problems were highlighted during the premiere episode of her Lifetime series, "The Houstons: On Our Own" ... which featured 19-year-old Bobbi slamming wine and slurring. The episode was taped a few months ago ... and our sources say the boozing has only gotten worse since the show wrapped.

During a tease for an upcoming episode, an emotional Pat Houston suggests taking Bobbi to California ... where Whitney received treatment from a drug counselor before she died.

Sources close to B.K. tell us ... they DON'T WANT Bobbi to see the same counselor, because they feel he did not help Whitney ... and will fail again with Bobbi.

Whitney Houston's family wants to put the singer's fortune on lockdown to stop Bobbi Kristina from blowing her inheritance ... and to protect BK from financial leeches.

Cissy Houston and Pat Houston, Whitney's mom and sister-in-law, filed a request this week to modify Whitney's will. Specifically, they want to change the distribution schedule of the estate ... estimated to be worth at least $20 million.

Sources close to the family tell TMZ ... Cissy and Pat filed the documents because they think the current will gives BK "too much too soon" -- and they don't think she has any need for that kinda cash now.

We're told the family also wants to "protect [Bobbi Kristina] from herself" ... because she's vulnerable. In the documents, they claim 19-year-old Bobbi "is a highly visible target for those who would exert undue influence over her inheritance."

Bobbi Kristina, Whitney's sole heir, is currently scheduled to get her inheritance in three chunks -- 10% when she turns 21, just under 20% at age 25 ... and the balance when she's 30.

In their petition, Pat and Cissy don't mention what specific changes they are seeking to the current payment schedule -- but they say Whitney's intent was "to provide long-tern financial security and protection" for her daughter.

Ray J crashed and burned the morning after the Billboard Music Awards ... and landed in the hospital ... TMZ has learned.

We're told Ray J was extremely upset after his confrontation with Whitney Houston's family -- notably Pat Houston -- during the awards ceremony. On Monday morning, someone went into Ray J's hotel room and realized the singer was "out of it" and couldn't get out of bed.

We're told Ray J was extremely disoriented and was immediately taken to the hospital by ambulance.

As for what happened ... it's looking like a combo of exhaustion and dehydration. Ray J had just returned from a quick, 32-hour round trip to China for business and when he landed he immediately drove 4 hours to Las Vegas for the awards show.

Ray J is still in the hospital. No word on when he'll be released.

Ray J was almost physically removed from the Billboard Music Awards last night after angry members of Whitney Houston's family ordered their security to get him away from them ... TMZ has learned.

Pat Houston's blood was boiling because she, Bobbi Kristina and other family members were seated next to Ray J, the person Pat believes was a very bad influence on Whitney. Minutes before the tribute to Whitney, Pat asked her security to remove Ray J from his seat, but he refused to budge.

Our sources say ... Pat's security summoned hotel security, along with several uniformed officers to physically remove Ray J. 

Just before push was about to come to shove, security warned Pat that things would likely get physical and it would almost certainly be caught on video, just as Whitney was about to be honored.  Sources say Pat then grudgingly recanted and Ray J kept his seat.

For his part, Ray J groused to friends, "Pat ruined what was a great opportunity to honor the woman who I loved."



11:40 AM PDT -- A rep for the Houston family tells TMZ ... Pat's assistant DID ask for Ray J to be moved from his seat ... but only after an official from Billboard told the family they needed to move to the seat that Ray J was already using.

Since Ray J had a ticket with the proper seat number, he refused to budge ... so Pat's assistant called for security to help sort out the situation.

The Houston family rep insists Pat does not have a problem with Ray J.

Whitney Houston's sister-in-law -- Pat Houston -- is waging war against Bobbi Kristina because she desperately wants to accept Whitney's Billboard Music Award on her behalf ... and only BK is standing in her way.

Sources closes to the situation tell TMZ ... Pat is trying to force herself into the spotlight by accepting Whitney's Millenium Award at the ceremony in Las Vegas tonight ... and producers of the show are pissed.

We're told the show really wants BK to accept the award and make the speech on the late singer's behalf ... but Pat won't stand for it and is making life hell for them as she tries to worm her way into the segment.

Sources tell us ... the show's producers feel BK is the best choice to represent Whitney's legacy and they're convinced Pat is simply exploiting the situation to get publicity for her upcoming reality show.