I am so sorry to hear you missed your mums funereal
I want you to know that I can not switch at will either. I think you will find that people who can, have usually done much work or have been taught to do so.
Like sandy said, my switches are brought on by stressful events, and I do not have any control over the switches. Sometimes I do next t have control over my body either. So although one of the introverted alters may be filling my mind with paranoid thoughts, another alter can still force my body to do things (sometimes) at other times my body is paralyzed.
The switches for me can be brought on by outside events. Like recently my daughter worked out herself (she is 6) that if she compliments my mothering like 'you are the best mum in the world' she can switch me from a tween back to her mother. But I can not internally make this switch occur myself.
I am also in a constant state of disassociation. This is what my Doc says causes the serve DA (Like you have described)
I really know what day it is, loose hours at a time, my short term memory is non existent. Right now (without looking at the calendar) I can only tell you one thing that happened yesterday.. And the rest is a blur.
I know how frightening it can feel, but since I learnt yo accept it, admit it, make light of it & tell my friends about it.. My stress levels have lowered & while its yet to make the DA better, the DA no longer causes stress (unless I push to remember stuff & get upset when I can't)
My calendar is my best friend!!! Sometimes I still get it wrong but it helps to create a timeline.
Just the other day a friend was reminding me of a convocation we were having at her place while she was painting the bathroom. I remember the convocation but have no memory of being in her home. She told me I was there helping & I believe her. But in my memory I was at home/my home having the convocation on the phone, and saw her painting through a pic she sent my phone..
Sure enough when I checked my messages, there was no picture that I thought she sent, only then did I have a vauge memory of standing in the door way chatting while she painted.
It used to drive me crazy.. It still does at times.. I FEEL crazy but I KNOW I'm just sick. It is an hour illness & we will get better.