Below is my own personal opinion from what I have learned from grief.
The short answer is, you will adapt to the pain which will always be a part of you. There are two important things I want you to know: 1) you will heal at your own pace, 2) you have the right to feel grief for as long as you choose. Grief over the loss of a loved one is a deep pain. The pain you feel is one of the deepest forms of love mixed with loneliness and fear. This is important to understand, because it helps you understand why you feel the way you do and why it doesn't go away like most things. Some people want to move on, but I am not one of those people. I have learned that losing someone causes a deep scar which reminds me of them. There is no correct way to grieve, however. Everyone is different. It is important to know you don't have to "move on" if you feel it makes you sad. One thing that is often not said that everyone gains in time is understanding that the person they lost is not really gone, they remain beside you. Perhaps that is why the pain feel less with time because you will see their signs. This is possibly why grief becomes easier, the fear lifts when we believe we have lost our dearly departed. We do not; they move to a different form. What remains is love and loneliness. The key to healthy grieving is learning how to manage the loneliness. See healing traditions for tips
Grief is best described as the tale of two wolves; darkness and light. The one the grows is the one you feed the most. The same is true about grief. If you dwell on negative aspects regarding the loss, your pain will remain greater over time and even manifest into something you can't control. If you feed positive energy regarding your loss, you will be amazed by how resilient your soul can be. You will be able to truly feel the one you have lost living in your heart, which will help with the loneliness. You may never feel them if you dwell in a negative place because it makes you blind to the messages around you.
Start with healing from someone with experience in loss or joining a local group for grief. When the time is right, let others help you heal. And if not people, consider a furry friend! A social aspect is one of the keystones to managing grief. Avoid being around people who are making it harder to heal or do not respect your burden. Positive vibes only.
Train your mind to see the positive in what remains and what is left to come.
Become proactive about your situation by doing things that will help you release your feelings in a healthy way. For example, find a peaceful place to visit and have a talk with the one you miss. Create them a piece of art which you can hold close. Go on long walks to ease the pain. And never underestimate the power of giving to others, charity as a form of healing a broken heart (animals, kids, families in need). Do this cause in the name of your dearly departed.
Write your feelings down. Some people keep a diary of things they want to say to the one the miss, or simply explain what they feel week by week.
This is one of the most profound experiences with death, and only those who have lost one they love deeply understand. They do return in another form to visit you. I did not fully understand the gravity of this, but I am now a believer. First, stop dismissing everything as "coincidence". That is a discredit to the person working very hard to reach out to you and robbing yourself the joy of seeing more messages. Second, pick yourself up and stay strong because a big message will be coming, and then another. Timing is everything with these little gems.
Look for the signature of the one you love. This could be a number associated with their death, a thing which you feel connected with them such as a color, animal or symbol. It may come in a dream which feels peaceful and fulfilling. It may come as something else entirely unexpected. Be patient. When you know, you know. Last, never be afraid to jumpstart the process by taking a peaceful moment, closing your eyes and quietly asking them to join you and that you miss them. Everyone's experience is unique and there is no science behind any of it to be explained.
“Don’t grieve. Anything you lose comes round in another form.” - Rumi