01/07/2008 at 05:00 AM EST
In the wake of Britney Spears
from Cedars-Sinai Medical Center, a subdued Kevin Federline
spent the weekend hunkered down at his Tarzana home with sons Preston, 2, and Jayden, 1.
Federline – who has been granted sole legal and physical custody of the boys following Spears's Thursday night meltdown
– was not spotted once outside of the house and, a source says, he's settled into "lockdown mode."
"He's freaked about people seeing his kids. It's just not happening right now," adds the Federline source. "His tight circle is even tighter right now. He doesn't even have his phone on."
The source described Federline's mood as "sad" and "freaked" over his ex-wife's breakdown. "If there was any kind of consolation at all, it was that [Britney] was in the hospital. But now she's out of there. He was shocked [she was released], but then again he wasn't. Because it's all about who she is. No one tells her anything."
Federline did have at least one guest over the weekend. His lawyer, Mark Vincent Kaplan, visited for a few hours on Sunday night. Upon leaving, Kaplan told photographers "the kids are well and Kevin is watching the football game."