Grief is very personal and very different for everyone.
You have not yet had time to process all this. Most people are rubbish at processing grief. They worry about the small stuff - like how much they will missed at work and will it impact the pupils. Or they get angry or try to find someone to be angry at.
You've had a major event in your life. You won't even know how it's going to affect you, until you start experiencing and realising life is different.
And you can't even beging to do that until the funeral happens.
Your pupils will turn up at school like normal. A substitute teacher will step in. Your colleagues will step in. Everyone you work with will try to make it okay for both you and your pupils.
But the sooner you schedule in time for you not to be okay, the easier it will be.
I don't know your family dynamics - but arranging a funeral or a gathering to scatter ashes can be physically and emotionally draining. Sometimes in a good way. It acts as a release.
If you feel discombobulated/ distant/ unsettled/ want to compartmentalise actions/ confused. You're not. You're just supressing emotions that will bite you in the backside.
So as much as no one grieves on cue and as expected - focussing on funerals, death rituals, might just help you more in the longer term.
I have an aquaintance/friend/colleague who is waiting for her very loved mother to die. For the past 5 months. The stress she is under is enormous. We've all seen the changes, but she thinks she's coping. She travels hundreds of miles every weekend. But she can't grieve because mum is not dead. She's got a set pattern waiting for the final death. She's outspoken in waiting for the final death. But it is consuming her. She's now such a tightly wound spring - that the company is putting in place counselling services and support for "the final event", because it's grief and denial and it's most raw.