Hi
@Wigan Lass, sorry to hear about your situation, it is a difficult one to deal with for sure. Does your Mum sundown i.e. get quite confused late afternoon early evening? Or was this a 'one off'? I am guessing the former as you say that you are 'continually anxious waiting for a phone call'.
If it was a recent development (past few days) or a one off perhaps speak to the GP and check for infections. If it is something more regular that has been going on for a while in different guises e.g. calling you to ask where she is, that is more problematic. I went through the same with my Mum for several months. I totally get that feeling of continuous anxiety, you are always on edge awaiting a call. Unfortunately there is no simple solution (if is isn't caused by an underlying infection), you just have to develop ways of dealing with it that work for Mum. My Mum often thought it wasn't her own bungalow and was worried about the 'owners' coming back, once I realised that I used to tell her they were my friends and wanted her to look after the place and she would then relax and I could get her to bed and stay until she got to sleep. I 'managed' it for a while but it became a daily event that she didn't recognise her own bungalow when she was sundowning and started leaving the house to get 'home'. We made the decision (with Mum) for residential care (we also considered 24 hour home care - but as she recognised the bungalow less and less it wasn't our preferred option). What surprised me most was that she had a much richer life in the care home and was far happier and the anxiety was managed so much better as the carers were there to comfort her if she became confused.
I think all you can do if you want Mum to remain living independently is to accept that you will get regular calls, it's a strange thing but once I accepted that it relieved the anxiety. I don't know if you have family that can help - perhaps you could draw up a rota to help Mum get to bed at night? So you can be assured she is tucked up and comfortable?
I wish you all the best, I know how emotionally and physically draining it can be. Stay strong.