Lamar Odom recently checked himself into rehab after hitting what sources call “rock bottom” for him. Radar Online got the scoop about what’s really going, and apparently it was his marriage with Khloe Kardashian that sent things over the edge.

Khloe first filed for divorce three years ago, amid reports the NBA star was cheating and using drugs.

“At times, Khloe has seemed to want to keep Lamar hanging on, but everyone around her tells her that it is just not fair to let him think that there is still a chance that the two of them will reconcile,” the source told Radar. “Her sisters tell her that she needs to let it go and let Lamar live his own life.”

Their divorce was finalized just last week, and now Khloe is dating  NBA star Tristan Thompson: “Khloe and Tristan dating really seemed to send Lamar over the edge,” the source said. “The holidays are particularly hard for him this year. His divorce is official and he’s not dating, so it’s easy for him to over-do it with the partying without anything keeping him in check… His plan to go to rehab was partly facilitated by his ex, Liza Morales, after talking over the past couple weeks. He’s been really trying to be there more for his kids, so everyone’s excited he is taking this step, and right before the holidays too.”

In regards to Lamar’s drug use, source adds, “He has been using though. This isnt just a check in to maintain sobriety. Lamar has not maintained sobriety for more than a month since he was hospitalized for his overdose. He still smokes weed nearly every single day!”

Last year, Lamar was hospitalized after overdosing on drugs and alcohol in a brothel outside of Las Vegas, reports Radar.  Fortunately, he made a speedy recovery. Hopefully he’ll do the same this time!