By Jen Heger - Breaking Celebrity News Assistant Managing Editor

Brooke Mueller insists she is "doing excellent" despite her ex-husband, Charlie Sheen's fears that her long standing drug addiction could end her life, Breaking Celebrity News is exclusively reporting.

As we previously reported, Mueller entered rehab for the 19th time earlier this month, reportedly for an addiction to Adderall.

In a text message to Breaking Celebrity News, the Florida socialite and mother to Sheen's twin toddler sons, Bob and Max, said she was "doing excellent" despite sparking concern from family and friends over her leaving rehab after only a few days of treatment.

Among those concerned is Sheen, who is telling friends he fears for his ex-wife's future if she doesn't get a handle on her addiction issues.

"Charlie has said he fears for Brooke's health and well being," a close source tells Breaking Celebrity News. "She obviously just isn't in a good place right now. Brooke is in absolute denial about her addiction to drugs. The disease is winning and Charlie feels powerless to do anything to stop Brooke from her down