I've been sticking to a diet of around 1200cal, & I've been working out 5dys a wk for months, & months now, & I've only lost a few lbs! Y can't I lose?

Increase calories . Too few calories and extensive exercise can cause a caloric depravation putting your body into a starvation mode. This will cause your body to preserve what calories you consume and result in poor weight loss. Speak with a personal trainer or dietitian and they can help you balance your intake with the amount of activity your performing to help you lose weight more effectively.
Keep a diary. Keeping a diary of how much you are eating is very helpful. If you are consuming 1200cal a day and exercising 5 times a week like 3-5 hrs of brisk walking, your underlying medical condition is normal and not loosing weight then you are probably at your platou and need to decrease your caloric intake and increase your exercise.