Don Cornelius -- No Suicide Note

Don Cornelius did not leave a suicide note at the home where he shot himself ... this according to multiple law enforcement sources.

We have been told by numerous people today that Don's health problems plagued him for years ... and the pain had become unbearable.

As we first reported, Don was discovered early this morning at his Sherman Oaks, CA home with a gunshot wound to his head.

The picture shows the ambulance that took Don to a nearby hospital, where he was pronounced dead early this morning.