WE are all different, our relationship with the person we lost is not the same as those around us and we greive in different ways from I think everyone does go into some kind of shock phase after something like this and as Sandra said perhaps your professional head is still in place because of that. Also i think its our brains way of protecting us to not allow us to feel the full impact in one instant hit.
We sometimes deal with it by a means of distraction - in a way the funeral itself does this, making arrangements, chosing music, flowers etc - its almost as though we are arranging a party for them and they will be present as normal - we know its not the case of course but are in a way thinking in those terms, what would they like -what music to pick how do we make the guests comfortable, feed them etc. After that sometimes there can be complex paperwork and sorting stuff out which defers things a bit longer then suddenly when it seems there is nothing left to do but grieve it hits us again.
Stating your uni course will help in a lot of ways, give you a new purpose and focus your mind elsewhere but its still really important to take time for grief too, otherwise there is a risk we simply dont move beyond denial and defer grief sometimes people do this for years and that can add to things like anxiety and depression .
However I suspect from your post you are already feeling anxiety that the sledgehammer will prevent you doing that but that doesnt have to be the case, your mum would have been proud of you considering doing it and to continue forward with it can be in a way a tribute too her as well as yourself of course.
There is a lot of expectation that there is a predicted pattern and a time and a grief process which is set - because as humans we like slots, and as a nurse perhaps dealing with physical or mental illness this is also something you expect, The grief theorys are not totally wrong but the order and the time period they suggest is one that fits into a pattern which isnt the reality of most peoples experiences.There are also some societal expectations which we dont match either.
Some people think grief stops with the funeral others after a year (because of some victorian values based on practicalities and outmoded ideas of decency and not reality at all)
It is almost as if you try and file case notes over and over again but some-one keeps sneaking in getting them out and throwing them all over the floor, so its a bit of a roller coaster of a journey.
When it does change from how you feel now, and it probably will, talking to your daughter will help both of you and its important to do so and also to let her see that it is fine to be sad, often when we are trying to be strong for others especially the young we mask our own feelings and teach them without trying too that our feelings are wrong or cant be expressed. Creating a memory box together is helpful as sifting through photos or things to put in there and sharing the stories around those things helps you focus on a whole life lived rather that its ending.
Coming here helped me a lot,and i hope we can help you as well, just having somewhere to write and knowing others have experienced some of the same things and you are not losing the plot can make such a difference and we will be here as long as you need us.