Dear HPearce,
There will be many people on this site who can relate to the feelings you are describing. My mum died in 2018 and I can remember how upset I was when weeks before Mother’s Day I saw all the cards and presents in the shops the first year after she died. Becasue I am Dutch, I was reminded of it twice because in Holland it is celebrated in May. Losing our mums is really hard and seeing others with their mums can make us feel the loss even more. There are no easy answers, but you may find it helpful to read this post from last year from one of the Sue Ryder staff members about coping with mother’s day: Coping with Mother's Day
I hope that despite your sadness you will still be able to enjoy what your children do for you on Mother’s day. Jo