Mother S*xually Abuses 13Year-Old Son For Four Years

Femi was born into a comfortable family but his father died when he was 13yrs old and ever since then his mother has been s*xually abusing him, which affected his relationship with people especially with females. He keeps to himself even at school.
His mother had warned him not to speak with anyone and not to have other friends. However, Femi didn’t understand why his mother was engaging in such act and he was too scared to talk to anybody about it, and for years, he has been carrying out his mother’s wish….sleeping with her.
The relationship continued for 4years before Femi finally gathered up courage to confide in a teacher he came across at a school program. When his mother was asked why she engaged in such dirty act she said:
“I am truly sorry,  I don’t want people to tag me as a promiscuous woman” so I decided to keep it within the house………… What kind of a mother s*xually abuses her son?
What should be done about a situation like this? Will Femi be able to get over this?