this talking to the loved one about it and just talking to them in general hits home with me as well. I hope you will not take it the wrong way, but I will venture something that has been passed on to me as well. Right now when you are feeling the way you do, it would be best to come up with some strategies for coping such as -
if you want to talk to him, do so. It might feel really weird to begin with, since he is not physically there. But do it anyway - you can do it out loud, just in your head or a combination, depending on how you feel or where you are. What worked for me was to set aside a certain time of the day for talking with Mum. Talk about whatever you feel at the moment. In the beginning I was talking a lot about how I felt, how unbearable, unbelievable etc. the situation felt. Then I moved on to my beliefs regarding the afterlife, such as they were / are = developing. Sometimes I talk to her about things I read or thought about, have seen, that I know she would like. Other times it is about daily life. Sometimes I ask her for protection or advice. Basically it is important to keep a semblance of the routine you had, whatever that was.
work out a belief system of your own, or if you follow some traditional set of beliefs, seek solace in that. It does not have to be something logical, right now the purpose is to make yourself feel like the connection has not been severed. Like others have said, you have been hurt to your core, so right now you need to heal. Later on when you build back your emotional strength, you can go back to logic, in case that is something that is holding you back right now. I know it was in my case. You may also find that even scientific opinions are not particularly clear cut about death. I personally believe that a person is aware at some deep level when they are passing from a state of existence to the other. In any case, science cannot tell you with absolute certainty that they do not know what is going on, because science has so far not worked out just what consciousness is. So you are free to believe what you want / what works for you.
if you have people around that are open to listen, accept their emotional help. Do not isolate yourself, if you can, at this time.
try to distract yourself at least once a day. Give yourself a short break from grieving by continuing with the most mundane routines of your day or have an unrelated chat with someone. I know it feels wrong and impossible, pretty much like a betrayal of him, but think of what he would like for you. He would like you to get better, all good parents want that for their children. He would most certainly not want you to keep suffering.
I found that another thing that keeps the connection alive is to continue doing something I either used to do together with Mum or something she liked to do that I can also do. There must be something like that you can do. Give it a try, see how it works for you.
try not to give in to self blame or regrets. If you had a strong connection, the sum is bigger than the parts. It is more important if he knew you loved and cared for him rather than the details of whatever might have been left undone or done wrongly.
ps - it does get better. It will never go away, but the pain will not be quite as sharp forever,