Each person suffers and deals with grief differently, I lost my wife of 27 years on Sept 13th 2017,I still tear up on occasions,remembering her. Grieve at you own pace, but seek help if it persists, as it may become depression.

Fortunately, up till now ..I don’t know. But I occasionally think about it, assuming my thoughts are not a trigger. It’s up to those like you to show me the way, as I fear that day

There’s no set time frame to go through the stages of grief. We are all individuals and cope in different ways. Be mindful of your needs and seek counseling if you need to.

How long will it lasts depends o n how long it takes for you to move to the next stage of the grieving process. Acceptance is the last step. Research grieving & work thru the stages. Get some professional help if you find yourself stuck in one stage. Horrible President Bill Clinton made mental illness a covered issue by insurance. Your loss is painful but not to you mother. Rejoice that she suffers no more.

It's different for different people. My mom passed last February 4th. We were as prepared as possible as she was 84 and in poor health.... But still.

You may want to see a grief counselor. I did and it definitely helped.

All grief is different and individual. Many have felt grief, but none know your experience. There are some good suggestions here. Just know that no matter how you respond, feel, or act, you are normal. Allow your inner self to guide you and take all the time you need; as already said, it may take years to lessen. Our thoughts are with you.

I’m sorry for your loss. Grief takes as long as it takes, it’s different for each of us. There’s no ‘right’ way to deal with it. Nor do the stages go in order.
When my brother died 3 years ago, the grief was unbearable. I had support from friends and family, plus therapy and using coping measures such as, going for a drive, writing, adult coloring books, music...sometimes, I just cried, raged, let the grief out.
Hold on to your memories, and care for yourself while you get through the first months of grief. As @amisja says: it doesn’t go away. Just gets less intense over time.

So sorry...it never really goes. You jusr learn a new reality. Mine is 14 years on saturday