48 lbs. lost is great. But, of course, the last bit is the hardest. I'd say you've hit a plateau, but 4 months is a bit long for just a plateau. Since I don't know what your eating habits are, or if you are on any regular exercise plan, I can only suggest that maybe you step up the exercise. You're probably eating the right amount if you've already lost 48 lbs, but your body has evidently gotten used to what you're currently doing. I would add another 30 minutes a week of cardio to what you're already doing. It's not really very much over a week, but it might just be the little bit that gets your weight loss going again. Also, you need to consider what your goal is. Is it reasonable? Muscle is heavier than fat. And 164 with a unfit body is not the same as 164 and a fit body. 164 with a flabby body will look fat, and it will be. But 164 with a toned body could possibly be a good weight for you. It's just a thought. 
rtardif!! You’re so right about the exercise!, I "think" I eat right (about 1,300-1,400 cal. and mostly whole wheat, soy products, chicken, fish, and some vegetables (not a big fan
)) but I don’t exercise as much as I’m supposed to
. Because of my work
and being a full time student I spend most of my time sitting in a chair, anyways two weeks ago I started going to spinning classes 2-3 times a week for an hour, I hope that helps! 