OP Here:
Thank you for your responses here, particularly the last three ones.
They were very very helpful to read and I will take all of your advice to heart.

I’m sorry for your loss. I lost my dad when I was 30 y/o and got 3 days of bereavement (we really should offer more as a society than a few days). Obviously I needed more time off but I had to work to pay the bills. I wasn’t a very effective employee but it did serve as a distraction and the routine helped a bit but it was hard. At that time I also had a side hustle where I was around people and had to be happy and engaging - again this was hard but it kinda helped pretending for a few hours that I was happy. I’m sorry you have to pretend to be okay while grieving but hopefully it can momentarily distract you and give you a little routine at a very difficult time in your life.

Grief is fickle. Some moments you will be ok, and then you will feel guilty for feeling ok. Some moments you will have found yourself moving on, and then a wave of grief knocks you flat on your back. Even a year later, you may not be OK, but you will continue to live your life, because that's what you need to do.

I am sorry for your loss, and, your friend would not want your life to fall apart because of their death.

I would encourage you to find grief counseling (hospice offers this), to work through your feelings.

You won't get over it in one week, or two or five. It will be less fresh, but won't stop thinking of her at odd moments and you shouldn't expect that.

Toward the end of your week, decide what will help you refocus when you do think of her at work. Maybe it's "what would she say right now?" Or maybe it's just "nope, think about kittens." And then build in a set time after work - maybe after dinner - to spend 10 minutes looking at pictures of her or writing in a journal, because you're not trying to bottle it all up forever, just for the workday.

Good luck.