Oh Jo, this is so sad. Very sorry for your loss of two special people in your life. Your experiencing grief right now and that a really hard emotion to process, I can understand why you cannot sleep or eat. But do please try, if you don't give yourself some self care you could get a low immune system and become unwell. Griveing is very exhausting and without sleep you will feel so burnt out and unable to function. If you just try to eat and drink a little but that is a good start.
I recently lost my grandmother and could not visit her because of nursing home lockdowns. I couldnt go to her furneral either, it was online. I hadnt seen or spoken to her since feburary. Its so sad that we all have been depreived of family and friend contact for so long. I had to say goodbye to her online, never thought that it would be how it would end up.
There are some support from the national grief line that you can call for free 1300 845 745 , you may benefit from talking to a councillor about the sadness you are feeling. Again I am so sorry for your loss, my thoughts and payers are with you during this tough time.