Dear Aileen,
I believe your mom didn't want to see you in such sad feeling after she had to leave you alone , remember when she went to the Heaven with smiling.
Please don't let your mom feel so sad when she watch you, show to your mom that you can make it through and let her know you will be doing fine afterwards.
Go to have lunch and chart with your good friends, or walk around, take a mini trip to mountain, beach, hot spring, do yoga, finish some small project.... don't be alone, be with friends, focus something else, I understand it's not easy to do, it's so hurt whenever we try so hard not let our heart to get hurt again and again. I wish the heart would listen to what I want, as you know, usually we couldn't control our emotion......