After The Deathly Hallows, Draco’s life changed forever. The "cohabitation" with Lord Voldemort in the Malfoy villa before the battle, the atrocities that are insinuated in Rowling's story that they were made by the Death Eaters to those opposite them, and Crabbe's tragic death permanently removed Draco from his father.

After the events of the Battle of Hogwarts and the definitive fall of Lord Voldemort, Draco chose to distance himself from his father and married Astoria Greengrass, a pureblood witch. Draco and Astoria decided to completely remove from their lives the hatred for Muggles with which they had grown up with. So the family gatherings, according to Rowling, were highly charged.

Because of a curse that was chewing on the Greengrass family, they were delayed in having a baby. This curse either made conception impossible for a member of the Greengrass family or could be fatal to the woman in the event of pregnancy. Draco told his wife that he preferred to be the last Malfoy rather than have Astoria risk her life, but Astoria insisted on trying and so she became pregnant. The curse struck Astoria as soon as their son, Scorpius, was born.

Astoria was sick for several years and unfortunately, many rumors spread about the nature of her pregnancy. It even sounded like she couldn't have gotten pregnant by Draco, so, with a time machine, she traveled in the past to get pregnant by Lord Voldemort himself.

In the meantime, Draco did not work and remained at home raising Scorpius, as the vast fortune he had from his parents was more than enough for a family to live with. As a hobby, he had alchemy and collecting (but not using) objects related to the dark arts.

Draco and Astoria raised their son a different way than they raised themselves, and taught him not to pay attention to ancestry, as well as to be gentle and pleasant to all people. Astoria died when Scorpius was preparing to start his third year of study at Hogwarts.

Of course, Draco could never be friends with Harry, Ron, and Hermione, but in adulthood, they learned to respect each other.

Source : https://www.quora.com/What-happened-to-Draco-Malfoy-after-Harry-defeated-Voldemort

https://harrypotter.fandom.com/wiki/Astoria_Malfoy 

Claire Angelina Herkins, HDN Writer and Public Affairs Manager