Diddy's Ex And Mother Of 3 Of His Children, Kim Porter Found Dead In Her Home

7:00 PM PT -- Law enforcement sources tell TMZ, Kim went to bed early last night, because she wasn't feeling well and when family members went to wake her Thursday she was non-responsive.  Paramedics pronounced Kim dead at her home.

As for the cause ... we're told she was battling an illness -- either the flu or pneumonia -- over the last few days and was being treated with Saline and vitamins. Authorities are also looking at a recent trip Kim took to Africa, to determine if she contracted a disease. 

No illegal drugs were found.