We know Rob Kardashian is going through a lot, and it's taking a toll on Khloe. She shared an adorable snap of the two in a throwback Thursday Instagram post.

We told you on Tuesday Rob's sis was "shaken to her core" over his partying and drug use.

"Khloe can't think right now; she's just in disbelief right now that her little brother is going through these issues," an insider revealed to Hollywood Life.

"She realized he's been troubled for a long time now but was in the dark that it's reached this level," our insider reveals. "She can't deal. She feels low because she's been through this before with her ex and it's all too familiar and another earthquake that's rocked her core."

We also knew that Khloe was reaching out to him non-stop after he abruptly left Kimye's wedding. It was later reported he was not speaking with his sisters.

"She would drop her entire life for him," the source added, and Rob "knows that."

"And that's what killing her the most. He has everything, every resource of Khloe's and the family's at his disposal but choosing not to use them. It's a slap in the face."

Rob was pictured smoking weed and drinking sizzurp with friends. He is seen sitting on a couch, passing a suspicious-looking cigarette to a friend. On a nearby table appears to be multiple cups of sizzurp, a combination of codeine-packed cough syrup and soda.

"He'd just lie around his place smoking weed, doing drugs, watching movies and eating. He said he 'needed' the pills," the friend explained.

He even left sister Kim's wedding to Kanye West early with reports claiming he was too embarrassed to pose in pictures, but Kardashian's friend said that was not the only reason.

"The reason he left Kim's wedding wasn't just that he was embarrassed to pose in photos," the insider revealed to the mag. "He only knows how to party to excess. He is so depressed and needs help."

Do you think they are making up? Let us know why or why not below!