Help to improve workout and diet?

I've recently started working out at home to lose fat and gain muscle. I usually run on the treadmill and do a core workout that we do in ultimate frisbee which for me works really well. I run around 2 miles at 5-6 speed and then cool down with a minute or so walk on 3 speed then i do my core workout which is: 20 touch touch crunches, 20 suitcase crunches, 20 left oblique crunches, 20 right oblique crunches, left right crunches (don't know the proper name but you basically do a sit-up on the right and then the left and that would count as one), 3 leg lifts holding for 30 seconds each, and between each of these i do 10 pushups. I currently take whey protein after my workouts, it's 28 grams per serving. I wanted to know if i'm getting enough protein (i'm 155 lbs) and i wanted to know weather i should take my protein shake before my workout as opposed to after it, i don't know the pros and cons of this but some say it is better. I've been doing this for about a month and i haven't noticed a significant change in my weight, and i doubt it is because i've gained muscle and loss fat because i don't look more muscular than i was before and i don't have much less blubber. I think it might be my diet but I eat a low calorie, low fat, and generally low carbs diet, unless i'm doing something wrong. I get anywhere from 30 - 60 grams of protein on a given day. Any help on improving my workout and improving my diet?