I also wish you comfort and support. Gardens can do much to soothe the spirit.
For fall blooming plants you might try cyclamen which form a fall blooming ground cover. Turtlehead (chelone) is a perennial which blooms in the fall in pinks, purples or white. I just tried turtlehead this year and was quite pleased with how they did. I don't know how they would do in Ireland, but I've looked at a hardiness zone map and it is similar to what we have in the South.
I have seen that the True Forget-Me-Nots also did well and bloomed in the fall. Unlike the turtlehead they are evergreen in my garden.