Complex sentence: At 16 he set up home on his own, against the wishes of Social Services, after a traumatic event at the age of 18 he became homeless and lived on the streets but by 20 he'd recovered his life and bought his first flat.
Split into simpler sentences: At 16 he set up home on his own, against the wishes of Social Services. After a traumatic event at the age of 18 he became homeless and lived on the streets, but by 20 he'd recovered his life and bought his first flat.