I have experienced a lot of isolation and I know I would not feel sad if many people passed away.

However some would matter. How do we handle grief, especially when we have PTSD so we experience things at much greater intensity. Particularly when there's a feeling of guilt. Just yesterday I came across a woman who gave permission to pull the plug on her dad. 

The first thing is to try to take good memories of them and highlight them in your mind. Share it. Write it down. It can be a way other people and even you grow through the memory of your loved one. 

Another important tool, I personally know of the afterlife, not how the Christian religion sees it by the way. In my understanding, if you do a good thing in their memory it increases their pleasure in the afterlife. And they will be grateful to you for that. It's a way for you to maintain a special relationship with your loved one. Not by speaking to a medium or psychic. This can give you satisfaction as being a vehicle of good for your loved one. 

When you feel sad it's not a bad thing and you shouldn't be angry at yourself. There's so much more but this is what's on my mind for now. All questions are welcome