The last paragraph touched me to the core.
Firstly, I am sorry for your loss but I want to congratulate you for being open about it.
We always fall short of time for expressing and accomplishing things. It's also true that we tend to miss out on the littlest things that actually end becoming the most precious ones with the passing of time.
How to cope with the loss? Maybe we could work on the foundation of embracing just the energies of the person rather than his/her physical existence. Moe you are dependent on their physical contribution, less you are grateful for their blessings and vibes.
We could start cherishing small things and start normalizing death as a part of our life.
How to do this? There is no universal answer. Maybe you have to explore that with subjective value of upbringing. Tell them that you love them but also tell them that we all are going to die and end up becoming nothing but memories.
Find your own coping mechanisms after accepting the fact that death is the beginning of a new life. Hope this helps.