One way is to think about taking life one hour at a time. Otherwise life becomes highly overwhelming when you think of all the various things, even small tasks, that you have to get through. Everything seems really frightening and daunting and unpleasant when you have this heavy grief burdening you always and so taking life one hour at a time might help you get through just a few things at a time while keeping your sanity in tact. It might seem unbearable to go on for weeks and months and years, but perhaps to just go on another hour might seem more realistic and doable in your grieved state of mind.
As the days pass, try to take life one day at a time. Do not think heavily of the future and all of the various obstacles in it that are to come, but instead spend each day with just that day in mind and accept the comfort of friends and family that they are willing to give that day. If you feel as though your heart has been shredded and ripped from your chest and that it is taking a mental and bodily toll on you, then taking it one day at a time will give you just enough strength to make it through just that one day. You will not have to overwhelm yourself with the notion of having to deal with this pain forever, but just that one day and when the day comes to an end you can be glad that you made it and the next day start all over again.
Though you may not feel like living anymore, you need to make sure that you take care of yourself and that you eat and get enough sleep and keep yourself away from substances like alcohol and drugs and any stimulating and possibly addictive item. You don’t want to form any kind of crutch or way to numb the pain because that is really just digging a deeper hole for yourself that will take even longer to climb out of. You need to make sure that you eat and that you take rest and that you accept the food that your loved ones are encouraging you to eat.
This will take effort on your part, as most likely you will not want to eat anything at all and will lose all motivation for it. But, make sure that you do take care of yourself. And this means your mental health, as well. There will be times that you most likely feel yourself start to break or lose all sanity and these are the times that you need to make sure you take care of yourself. Do something positive immediately. Go sit outside and stare at a beautiful sky, or read a book, watch a movie, do anything positive to try and soothe your mind.
Finally, try to have faith and believe in something. Studies show that having faith can help immensely with the coping process, as people begin to try to make some sense of what has happened and find some peace thinking that it was meant to be or that one day things will be ok. It does not matter what religion you practice or if you even practice one, but having faith in something will get you through this.