Learning to hockey stop?

i have been skating for a couple months now and i am pretty comfortable going forward and i am starting to get a lot better at going backwards. however, everytime i try to stop, i end up just going in a circle to slow my self down. my coach told me to "make snow" and everytime i try, my skate gets caught in the ice and i just lose my balance. i havent had my skates sharpened since i got them a couple months ago. but i was wondering if i need to distribute my weight differently than what i am doing now. also i think that i need to use my inside edge when i stop, but my coach didnt really explain it that well. my next practice if i am still having trouble then i am going to ask her for help but do you have any suggestions for me?