How many heirs did Augustus lose before his death in August 14 AD?

Augustus Caesar was a great Roman emperor. He married Scribonia at the young age of 23 in 40 BC. Their daughter Julia was born in 39 BC. Augustus would divorce Scribonia and marry his beloved Livia. She was the wife of Tiberius Claudius Nero. They had a son Tiberius.

Augustus compelled Nero to divorce Livia while she was carrying his second child. Augustus and Livia lived together for 52 years till Augustus died. They had no kids. Augustus still had his daughter Julia.

Augustus died in 14 AD. Prior to dying, he was determined to be succeeded by someone with his blood, but he had no sons. He made his daughter Julia marry his sister Octavia’s son Marcellus to get a heir. Marcellus died after 2 years. Then Julia was married to Agrippa; he was a very trustworthy friend of Augustus. Later Augustus adopted Gaius and Lucius, sons born to Julia and Agrippa. A third son Agrippa Postumus, who would later be adopted, died within days of Augustus' death. Augustus had initially hoped that the Empire would go to either Gaius or Lucius once the person was old and could manage. But Agrippa died in 12 BC before his sons grew up.

With no blood relations, Augustus turned to Tiberius, the eldest son of his wife Livia. He forced Tiberius to divorce his wife; he had him marry Julia. By this time Augustus was 67, he then adopted Tiberius officially as his son and heir. When Augustus died, Tiberius became his successor. He killed his stepson and his natural contender Agrippa Postumus.