No you aren’t being irrational. Grief will come at you with a whole range of emotions, you can’t plan for how it will affect you.
My mum died of an aneurysm - collapsed in my arms one sunny afternoon and was dead two days later.
I honestly think I could sunk into a pit of despair and stayed there forever. My best friend, my mum, the wisest kindest most beloved grandmother to my children - just gone like that, with no time for a proper goodbye. It was so sudden I was the only one who saw her in hospital before she died - my dh didn’t even pop in because he was looking after the kids. So it was just me at the bedside for those two days, waiting for her body to finally find some peace.
Unfortunately I was about to start a new job so I only had two days to “recover” after that - new employer didn’t do any kind of favours to new joiners on probation.
So I was at work making nice and learning my new job in the daytime, then over at my mum’s place in the evenings cleaning the kitchen, doing her laundry and sobbing the entire time. I had only just weaned my toddler so there was the added trouble of two young bereaved kids to deal with (“why isn’t granny coming for dinner with us today, when will she be better, is she on holiday”). My dc2 still asks me when the doctors will make granny better even though he hasn’t seen her for a year.
What I remember most was exhaustion and being unable to face any social situations for a long time - about 15 months. The only things I did were for my kids, and then it was just going through the motions.
Luckily my dh was amazing, and I will forever be grateful to him for the emotional sticking plasters and the encouragement to “take each day as it comes”, “put one step in front of the other”, “here’s a cup of tea, I’m taking the kids to see PIL so you can have the weekend to go to church and cry and then mow the lawn at your mum’s house”.
There was a lot of tough love in there, but I think it pushed me through those first six months.
I did try to find a grief counsellor but after three of them blanked my email enquiries I gave up and did my own thing.
I am still absolutely heartbroken but I’ve found a way to keep going. Not sure if this is helpful as I honestly think every situation is different and the only advice I can give is, do what YOU need to do. Only you can know what that is.