Everybody Ain't Your Friend by Tanisha Stewart

Mia thinks her life is completely normal. She has a loving boyfriend, great and supportive friends, and a close relationship with her mother. Things take an interesting turn, however, when she is almost run down by a car one day.
Then come the messages from an untraceable number.
Not to mention the heartbreaking secret that is revealed shortly thereafter.
Suddenly, everything that Mia thought was right in her life goes wrong. She has no idea why, but she needs to find out, before her secret stalker decides her time is up.