Dear Mandy B
You are kind to offer support to others while going though such a huge loss yourself.
Losing parents is one of the hardest things one has to face in life, and to be isolated makes matters worse, the distance and frustration very much takes its toll - on all, both you and your parents.
My own best friend passed away recently, which is not the same as a parent I know, but I was not able to see him and could only talk via phone when the only one on the ward was not being used. Even so I found he was as concerned about the effect his passing was gong to have on his mum and dad, and friends such as myself. He looked on his passing as natural and accepted it.
I hope there was someone where your parents were who could talk to them about everyday things and leave them feeling more at peace. I'm sure they would have been very aware of your love, even if they could not feel a hug or even your hand. After all your have been part of each others lives for a a very long time and they wold know you..
There is a good service
Griefline on 1300 845 745
which can sometimes help, simply by talking. They are experienced and I'd add them to Sophie_M's excellent recommendations
You mentioned family, I hope there is someone there who you can support and who can in turn support you.
There are no real words, all I can suggest is a link. I wish there was more