You most probably have hirsutism which is caused by an imbalance of various hormones, the most common of which represents as polycyctic ovarian disease. A more detailed history is required and a few tests need to be carried out including sonography of the pelvis, testosterone levels, DHEAS, LH/FSH & Insulin levels etc. Lifestyle change and medication would help your case. You can visit a dermatologist for further enquiries. For your dark hair, you may undergo laser hair removal sessions, which will delay the growth a bit, but your main priority should be to deal with your primary underlying condition.