Dear Kate,
So sorry to hear about your dad
and that you must be feeling so alone and so worried about your mum. I think all any of us can do at the moment is try to communicate as often as we can using any means available, be it Skype, Whatsapp, a phone call or just an old-fashioned card or letter.
I lost my own dad when I was 24, so do have some idea what you may be going through. It is very hard to lose a parent at any age, let alone when still so young. The difficult thing for you must be being separated from your mum. My advice would be to talk as often as you can and support one another as well as you can at a distance.
As Emz and Karena have said, grief is a hard long process under normal circumstances,which we are definitely not in now. So be as kind as you can to yourself. It might help to write a letter to your dad and tell him all the things you would have liked to say to him if you had had the chance. It helps to write it down and does bring some relief in my experience.
As Karena suggests, being out in nature helps too.I found walking in the park helped after I lost my mum and found my way here two years ago. It helped me just to know that other people understood how I was feeling too, so I hope you can take some comfort in that.
It must be very hard to process all this under the current lockdown restrictions, but we are here for you and will help as much as we can to help you get through this terrible time.
Sending strength and an understanding hug.