Lamar Odom is holed up in a private home in a gated community 100 miles from L.A. ... and his life is now revolving around smoking crack and partying with 2 young women -- and he's intimate with one of them.

Multiple sources privy to Lamar's current state tell TMZ ... Lamar has a driver who is regularly shuttling back and forth from L.A. to his rental home with one purpose -- scoring drugs, including crack.

We're told Lamar is so paranoid ... he insists the driver only buy small quantities of crack at a time, so as not to draw too much attention to him -- and that means frequent trips to score the drug.

Lamar almost never leaves the home. He's smoking crack and partying with the 2 women, both in their early 20s. His life now revolves around smoking crack and listening to rap music.

Our sources say Lamar is extremely paranoid about getting caught. He believes people -- not the 2 girls -- are watching him so he's using a phone app that allows him to text people but the texts are automatically deleted once the texts are read. The app also notifies Lamar if they try and screenshot the message.

Lamar's best friend is also staying at the house.

We're told Lamar has been living in 3 different residences in the last 2 months -- partly because he feels if he stays on the move he won't get caught.

As for Khloe ... we're told Lamar isn't worried that she'll leave him. He says he knows she loves him and has stood by him throughout the entire drug saga so he's convinced she won't abandon him now.