I understand where your coming from because I still miss my mom and she's been gone for 16 years. Find something that you enjoy doing with your mom and do that activity whenever you find yourself missing her.
Have you tried GriefShare.org. I have found that has helped a lot since I had lost first my Dad at 17. Then three years ago I lost my older brother and 11 months after that my mother. If you go to their website and put in your zip code they give you support groups in your area. It's a 13 week program. You view a video and then they have discussion on the video. Then there is a workbook with what they Call Mourning to Joy exercises to help you through on your journey. It also mentions journaling. It also has a biblical aspect to it. It helps to validate all the feelings your are feeling right now. Know you are not alone in those feelings .
I have one younger brother he has very little to do with me. Visited me once in the hospital haven't heard from him since being home only once to find out if I had paid the AAA membership because his car quit in him. Thing is to rebuild your support system.
How long have you felt like this? You could have complicated grief. I experienced that, and the grief group sponsored by my local hospice was wonderful. I got to express all the stuff I felt without being judged. Maybe look into something like that in your area?
HAve you tried bereavement counselling? I was offered it when my mum died and I refused it as I didn't see the point but now 20 months on and I've just been diagnosed with depression and anxiety. I've never had this in my life and I'm 49 years old. I just don't want to live with out her it's too hard. I have a husband I love dearly and a grown up son. I have support but I just can't cope. I really think I should ave had the counselling in the first place....
Talk about it, write about it, find new activities that give you a sense of purpose. Help someone or something. Helping others is therapeutic and shows us our true value. It takes as long as it takes and it will not go away overnight. The saying that time heals all wounds is not entirely true, especially if the wound is still bleeding.