Hi Shaza,
I'm so so sorry to hear about your mom. I lost my dad a few years ago very unexpectedly, and it turned my world upside down. The loss of a parent can be very hard to bear, and as someone said to me at the time, it is not something one understands unless you've been through it.
Perhaps there are other close friends or family members who can support your dad also? I know that, for me, my grieving process at losing my dad was entirely different to that of his partner's, or even my siblings. I believe that grief, and coming to terms with a loss like this, is something that we all deal with differently - even if you're grieving the same person and it can be a unique, and by definition isolating experience.
The sense of isolation is very normal - as I said I have siblings, and I felt incredibly alone when dad died. It seems so silly, given that I was 37, married, dc, job etc - but my first and most overwhelming thought was "who's going to take care of me now?" - even though the days of him practically taking care of me were long gone.
It is very very hard, but like most of these things, the only way out is through. Try and take it one day at a time, look after yourself as best you can - eat, sleep, rest. Grieve. Try not to worry about the funeral yet, you will cope with it on the day and for me it was an important part of the process of saying goodbye.
xxx