Why do I become obsessed with people, is it a form of OCD where you're infatuated by a lot of people that you meet?

Needy. Sounds like you are more than usually needy of attention/affection. Now, needing attention and affection are not abnormal, but when it interferes with normal functioning it is a problem that could be helped by seeking help from a mental health therapist.
OCD. May be potentially a problem . Ocd is aproblem when it interfers with others or is consuming your day and disrupts normal functioning. Some patients with OCD may be higly functiong and don;t reuquire treatmnet but other need eval and treatment. It depends on your level of functiong . But if concerned about it it would be best to seek medical attention or counseling.