gness. You say, in effect, that there is not much love lost between you, but if that was really the case, you would not be feeling guilty.
I went to a funeral today where the deceased, an 87 year old woman, was a real so-and-so towards her family over the years and yet all three of her 'children', all in their sixties, were in tears. (She was not related to me).
You only have one mum and we cannot get away from that.
All you can do is have that wine, relax and prepare yourself for the next visit.